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862 lines
31 KiB
C
862 lines
31 KiB
C
/*
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* copyright (c) 2001 Fabrice Bellard
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef AVFORMAT_AVIO_H
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#define AVFORMAT_AVIO_H
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/**
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* @file
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* @ingroup lavf_io
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* Buffered I/O operations
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*/
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#include <stdint.h>
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#include "libavutil/common.h"
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#include "libavutil/dict.h"
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#include "libavutil/log.h"
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#include "libavformat/version.h"
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/**
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* Seeking works like for a local file.
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*/
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#define AVIO_SEEKABLE_NORMAL (1 << 0)
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/**
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* Seeking by timestamp with avio_seek_time() is possible.
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*/
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#define AVIO_SEEKABLE_TIME (1 << 1)
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/**
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* Callback for checking whether to abort blocking functions.
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* AVERROR_EXIT is returned in this case by the interrupted
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* function. During blocking operations, callback is called with
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* opaque as parameter. If the callback returns 1, the
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* blocking operation will be aborted.
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*
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* No members can be added to this struct without a major bump, if
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* new elements have been added after this struct in AVFormatContext
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* or AVIOContext.
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*/
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typedef struct AVIOInterruptCB {
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int (*callback)(void*);
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void *opaque;
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} AVIOInterruptCB;
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/**
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* Directory entry types.
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*/
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enum AVIODirEntryType {
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AVIO_ENTRY_UNKNOWN,
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AVIO_ENTRY_BLOCK_DEVICE,
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AVIO_ENTRY_CHARACTER_DEVICE,
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AVIO_ENTRY_DIRECTORY,
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AVIO_ENTRY_NAMED_PIPE,
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AVIO_ENTRY_SYMBOLIC_LINK,
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AVIO_ENTRY_SOCKET,
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AVIO_ENTRY_FILE,
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AVIO_ENTRY_SERVER,
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AVIO_ENTRY_SHARE,
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AVIO_ENTRY_WORKGROUP,
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};
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/**
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* Describes single entry of the directory.
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*
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* Only name and type fields are guaranteed be set.
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* Rest of fields are protocol or/and platform dependent and might be unknown.
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*/
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typedef struct AVIODirEntry {
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char *name; /**< Filename */
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int type; /**< Type of the entry */
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int utf8; /**< Set to 1 when name is encoded with UTF-8, 0 otherwise.
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Name can be encoded with UTF-8 even though 0 is set. */
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int64_t size; /**< File size in bytes, -1 if unknown. */
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int64_t modification_timestamp; /**< Time of last modification in microseconds since unix
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epoch, -1 if unknown. */
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int64_t access_timestamp; /**< Time of last access in microseconds since unix epoch,
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-1 if unknown. */
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int64_t status_change_timestamp; /**< Time of last status change in microseconds since unix
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epoch, -1 if unknown. */
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int64_t user_id; /**< User ID of owner, -1 if unknown. */
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int64_t group_id; /**< Group ID of owner, -1 if unknown. */
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int64_t filemode; /**< Unix file mode, -1 if unknown. */
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} AVIODirEntry;
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typedef struct AVIODirContext {
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struct URLContext *url_context;
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} AVIODirContext;
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/**
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* Different data types that can be returned via the AVIO
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* write_data_type callback.
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*/
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enum AVIODataMarkerType {
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/**
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* Header data; this needs to be present for the stream to be decodeable.
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*/
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AVIO_DATA_MARKER_HEADER,
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/**
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* A point in the output bytestream where a decoder can start decoding
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* (i.e. a keyframe). A demuxer/decoder given the data flagged with
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* AVIO_DATA_MARKER_HEADER, followed by any AVIO_DATA_MARKER_SYNC_POINT,
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* should give decodeable results.
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*/
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AVIO_DATA_MARKER_SYNC_POINT,
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/**
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* A point in the output bytestream where a demuxer can start parsing
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* (for non self synchronizing bytestream formats). That is, any
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* non-keyframe packet start point.
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*/
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AVIO_DATA_MARKER_BOUNDARY_POINT,
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/**
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* This is any, unlabelled data. It can either be a muxer not marking
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* any positions at all, it can be an actual boundary/sync point
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* that the muxer chooses not to mark, or a later part of a packet/fragment
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* that is cut into multiple write callbacks due to limited IO buffer size.
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*/
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AVIO_DATA_MARKER_UNKNOWN,
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/**
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* Trailer data, which doesn't contain actual content, but only for
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* finalizing the output file.
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*/
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AVIO_DATA_MARKER_TRAILER,
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/**
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* A point in the output bytestream where the underlying AVIOContext might
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* flush the buffer depending on latency or buffering requirements. Typically
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* means the end of a packet.
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*/
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AVIO_DATA_MARKER_FLUSH_POINT,
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};
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/**
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* Bytestream IO Context.
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* New fields can be added to the end with minor version bumps.
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* Removal, reordering and changes to existing fields require a major
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* version bump.
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* sizeof(AVIOContext) must not be used outside libav*.
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*
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* @note None of the function pointers in AVIOContext should be called
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* directly, they should only be set by the client application
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* when implementing custom I/O. Normally these are set to the
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* function pointers specified in avio_alloc_context()
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*/
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typedef struct AVIOContext {
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/**
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* A class for private options.
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*
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* If this AVIOContext is created by avio_open2(), av_class is set and
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* passes the options down to protocols.
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*
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* If this AVIOContext is manually allocated, then av_class may be set by
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* the caller.
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*
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* warning -- this field can be NULL, be sure to not pass this AVIOContext
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* to any av_opt_* functions in that case.
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*/
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const AVClass *av_class;
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/*
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* The following shows the relationship between buffer, buf_ptr,
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* buf_ptr_max, buf_end, buf_size, and pos, when reading and when writing
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* (since AVIOContext is used for both):
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*
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**********************************************************************************
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* READING
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**********************************************************************************
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*
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* | buffer_size |
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* |---------------------------------------|
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* | |
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*
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* buffer buf_ptr buf_end
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* +---------------+-----------------------+
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* |/ / / / / / / /|/ / / / / / /| |
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* read buffer: |/ / consumed / | to be read /| |
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* |/ / / / / / / /|/ / / / / / /| |
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* +---------------+-----------------------+
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*
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* pos
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* +-------------------------------------------+-----------------+
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* input file: | | |
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* +-------------------------------------------+-----------------+
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*
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*
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**********************************************************************************
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* WRITING
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**********************************************************************************
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*
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* | buffer_size |
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* |--------------------------------------|
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* | |
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*
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* buf_ptr_max
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* buffer (buf_ptr) buf_end
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* +-----------------------+--------------+
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* |/ / / / / / / / / / / /| |
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* write buffer: | / / to be flushed / / | |
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* |/ / / / / / / / / / / /| |
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* +-----------------------+--------------+
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* buf_ptr can be in this
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* due to a backward seek
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*
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* pos
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* +-------------+----------------------------------------------+
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* output file: | | |
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* +-------------+----------------------------------------------+
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*
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*/
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unsigned char *buffer; /**< Start of the buffer. */
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int buffer_size; /**< Maximum buffer size */
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unsigned char *buf_ptr; /**< Current position in the buffer */
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unsigned char *buf_end; /**< End of the data, may be less than
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buffer+buffer_size if the read function returned
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less data than requested, e.g. for streams where
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no more data has been received yet. */
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void *opaque; /**< A private pointer, passed to the read/write/seek/...
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functions. */
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int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
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int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
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int64_t (*seek)(void *opaque, int64_t offset, int whence);
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int64_t pos; /**< position in the file of the current buffer */
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int eof_reached; /**< true if was unable to read due to error or eof */
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int write_flag; /**< true if open for writing */
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int max_packet_size;
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unsigned long checksum;
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unsigned char *checksum_ptr;
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unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
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int error; /**< contains the error code or 0 if no error happened */
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/**
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* Pause or resume playback for network streaming protocols - e.g. MMS.
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*/
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int (*read_pause)(void *opaque, int pause);
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/**
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* Seek to a given timestamp in stream with the specified stream_index.
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* Needed for some network streaming protocols which don't support seeking
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* to byte position.
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*/
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int64_t (*read_seek)(void *opaque, int stream_index,
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int64_t timestamp, int flags);
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/**
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* A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
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*/
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int seekable;
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/**
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* max filesize, used to limit allocations
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* This field is internal to libavformat and access from outside is not allowed.
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*/
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int64_t maxsize;
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/**
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* avio_read and avio_write should if possible be satisfied directly
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* instead of going through a buffer, and avio_seek will always
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* call the underlying seek function directly.
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*/
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int direct;
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/**
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* Bytes read statistic
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* This field is internal to libavformat and access from outside is not allowed.
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*/
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int64_t bytes_read;
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/**
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* seek statistic
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* This field is internal to libavformat and access from outside is not allowed.
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*/
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int seek_count;
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/**
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* writeout statistic
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* This field is internal to libavformat and access from outside is not allowed.
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*/
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int writeout_count;
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/**
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* Original buffer size
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* used internally after probing and ensure seekback to reset the buffer size
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* This field is internal to libavformat and access from outside is not allowed.
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*/
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int orig_buffer_size;
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/**
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* Threshold to favor readahead over seek.
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* This is current internal only, do not use from outside.
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*/
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int short_seek_threshold;
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/**
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* ',' separated list of allowed protocols.
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*/
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const char *protocol_whitelist;
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/**
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* ',' separated list of disallowed protocols.
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*/
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const char *protocol_blacklist;
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/**
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* A callback that is used instead of write_packet.
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*/
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int (*write_data_type)(void *opaque, uint8_t *buf, int buf_size,
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enum AVIODataMarkerType type, int64_t time);
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/**
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* If set, don't call write_data_type separately for AVIO_DATA_MARKER_BOUNDARY_POINT,
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* but ignore them and treat them as AVIO_DATA_MARKER_UNKNOWN (to avoid needlessly
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* small chunks of data returned from the callback).
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*/
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int ignore_boundary_point;
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/**
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* Internal, not meant to be used from outside of AVIOContext.
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*/
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enum AVIODataMarkerType current_type;
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int64_t last_time;
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/**
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* A callback that is used instead of short_seek_threshold.
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* This is current internal only, do not use from outside.
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*/
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int (*short_seek_get)(void *opaque);
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int64_t written;
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/**
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* Maximum reached position before a backward seek in the write buffer,
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* used keeping track of already written data for a later flush.
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*/
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unsigned char *buf_ptr_max;
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/**
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* Try to buffer at least this amount of data before flushing it
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*/
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int min_packet_size;
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} AVIOContext;
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/**
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* Return the name of the protocol that will handle the passed URL.
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*
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* NULL is returned if no protocol could be found for the given URL.
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*
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* @return Name of the protocol or NULL.
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*/
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const char *avio_find_protocol_name(const char *url);
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/**
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* Return AVIO_FLAG_* access flags corresponding to the access permissions
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* of the resource in url, or a negative value corresponding to an
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* AVERROR code in case of failure. The returned access flags are
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* masked by the value in flags.
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*
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* @note This function is intrinsically unsafe, in the sense that the
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* checked resource may change its existence or permission status from
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* one call to another. Thus you should not trust the returned value,
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* unless you are sure that no other processes are accessing the
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* checked resource.
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*/
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int avio_check(const char *url, int flags);
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/**
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* Move or rename a resource.
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*
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* @note url_src and url_dst should share the same protocol and authority.
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*
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* @param url_src url to resource to be moved
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* @param url_dst new url to resource if the operation succeeded
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* @return >=0 on success or negative on error.
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*/
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int avpriv_io_move(const char *url_src, const char *url_dst);
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/**
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* Delete a resource.
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*
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* @param url resource to be deleted.
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* @return >=0 on success or negative on error.
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*/
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int avpriv_io_delete(const char *url);
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/**
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* Open directory for reading.
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*
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* @param s directory read context. Pointer to a NULL pointer must be passed.
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* @param url directory to be listed.
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* @param options A dictionary filled with protocol-private options. On return
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* this parameter will be destroyed and replaced with a dictionary
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* containing options that were not found. May be NULL.
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* @return >=0 on success or negative on error.
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*/
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int avio_open_dir(AVIODirContext **s, const char *url, AVDictionary **options);
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/**
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* Get next directory entry.
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*
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* Returned entry must be freed with avio_free_directory_entry(). In particular
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* it may outlive AVIODirContext.
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*
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* @param s directory read context.
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* @param[out] next next entry or NULL when no more entries.
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* @return >=0 on success or negative on error. End of list is not considered an
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* error.
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*/
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int avio_read_dir(AVIODirContext *s, AVIODirEntry **next);
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/**
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* Close directory.
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*
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* @note Entries created using avio_read_dir() are not deleted and must be
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* freeded with avio_free_directory_entry().
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*
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* @param s directory read context.
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* @return >=0 on success or negative on error.
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*/
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int avio_close_dir(AVIODirContext **s);
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/**
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* Free entry allocated by avio_read_dir().
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*
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* @param entry entry to be freed.
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*/
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void avio_free_directory_entry(AVIODirEntry **entry);
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/**
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* Allocate and initialize an AVIOContext for buffered I/O. It must be later
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* freed with avio_context_free().
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*
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* @param buffer Memory block for input/output operations via AVIOContext.
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* The buffer must be allocated with av_malloc() and friends.
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* It may be freed and replaced with a new buffer by libavformat.
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* AVIOContext.buffer holds the buffer currently in use,
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* which must be later freed with av_free().
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* @param buffer_size The buffer size is very important for performance.
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* For protocols with fixed blocksize it should be set to this blocksize.
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* For others a typical size is a cache page, e.g. 4kb.
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* @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
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* @param opaque An opaque pointer to user-specific data.
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* @param read_packet A function for refilling the buffer, may be NULL.
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* For stream protocols, must never return 0 but rather
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* a proper AVERROR code.
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* @param write_packet A function for writing the buffer contents, may be NULL.
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* The function may not change the input buffers content.
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* @param seek A function for seeking to specified byte position, may be NULL.
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*
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* @return Allocated AVIOContext or NULL on failure.
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*/
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AVIOContext *avio_alloc_context(
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unsigned char *buffer,
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int buffer_size,
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int write_flag,
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void *opaque,
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int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
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int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
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int64_t (*seek)(void *opaque, int64_t offset, int whence));
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/**
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* Free the supplied IO context and everything associated with it.
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*
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* @param s Double pointer to the IO context. This function will write NULL
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* into s.
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*/
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void avio_context_free(AVIOContext **s);
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void avio_w8(AVIOContext *s, int b);
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void avio_write(AVIOContext *s, const unsigned char *buf, int size);
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void avio_wl64(AVIOContext *s, uint64_t val);
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void avio_wb64(AVIOContext *s, uint64_t val);
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void avio_wl32(AVIOContext *s, unsigned int val);
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void avio_wb32(AVIOContext *s, unsigned int val);
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void avio_wl24(AVIOContext *s, unsigned int val);
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void avio_wb24(AVIOContext *s, unsigned int val);
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void avio_wl16(AVIOContext *s, unsigned int val);
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void avio_wb16(AVIOContext *s, unsigned int val);
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/**
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* Write a NULL-terminated string.
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* @return number of bytes written.
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*/
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int avio_put_str(AVIOContext *s, const char *str);
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/**
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* Convert an UTF-8 string to UTF-16LE and write it.
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* @param s the AVIOContext
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* @param str NULL-terminated UTF-8 string
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*
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* @return number of bytes written.
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*/
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int avio_put_str16le(AVIOContext *s, const char *str);
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/**
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* Convert an UTF-8 string to UTF-16BE and write it.
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* @param s the AVIOContext
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* @param str NULL-terminated UTF-8 string
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*
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* @return number of bytes written.
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|
*/
|
|
int avio_put_str16be(AVIOContext *s, const char *str);
|
|
|
|
/**
|
|
* Mark the written bytestream as a specific type.
|
|
*
|
|
* Zero-length ranges are omitted from the output.
|
|
*
|
|
* @param time the stream time the current bytestream pos corresponds to
|
|
* (in AV_TIME_BASE units), or AV_NOPTS_VALUE if unknown or not
|
|
* applicable
|
|
* @param type the kind of data written starting at the current pos
|
|
*/
|
|
void avio_write_marker(AVIOContext *s, int64_t time, enum AVIODataMarkerType type);
|
|
|
|
/**
|
|
* ORing this as the "whence" parameter to a seek function causes it to
|
|
* return the filesize without seeking anywhere. Supporting this is optional.
|
|
* If it is not supported then the seek function will return <0.
|
|
*/
|
|
#define AVSEEK_SIZE 0x10000
|
|
|
|
/**
|
|
* Passing this flag as the "whence" parameter to a seek function causes it to
|
|
* seek by any means (like reopening and linear reading) or other normally unreasonable
|
|
* means that can be extremely slow.
|
|
* This may be ignored by the seek code.
|
|
*/
|
|
#define AVSEEK_FORCE 0x20000
|
|
|
|
/**
|
|
* fseek() equivalent for AVIOContext.
|
|
* @return new position or AVERROR.
|
|
*/
|
|
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
|
|
|
|
/**
|
|
* Skip given number of bytes forward
|
|
* @return new position or AVERROR.
|
|
*/
|
|
int64_t avio_skip(AVIOContext *s, int64_t offset);
|
|
|
|
/**
|
|
* ftell() equivalent for AVIOContext.
|
|
* @return position or AVERROR.
|
|
*/
|
|
static av_always_inline int64_t avio_tell(AVIOContext *s)
|
|
{
|
|
return avio_seek(s, 0, SEEK_CUR);
|
|
}
|
|
|
|
/**
|
|
* Get the filesize.
|
|
* @return filesize or AVERROR
|
|
*/
|
|
int64_t avio_size(AVIOContext *s);
|
|
|
|
/**
|
|
* Similar to feof() but also returns nonzero on read errors.
|
|
* @return non zero if and only if at end of file or a read error happened when reading.
|
|
*/
|
|
int avio_feof(AVIOContext *s);
|
|
|
|
/** @warning Writes up to 4 KiB per call */
|
|
int avio_printf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3);
|
|
|
|
/**
|
|
* Force flushing of buffered data.
|
|
*
|
|
* For write streams, force the buffered data to be immediately written to the output,
|
|
* without to wait to fill the internal buffer.
|
|
*
|
|
* For read streams, discard all currently buffered data, and advance the
|
|
* reported file position to that of the underlying stream. This does not
|
|
* read new data, and does not perform any seeks.
|
|
*/
|
|
void avio_flush(AVIOContext *s);
|
|
|
|
/**
|
|
* Read size bytes from AVIOContext into buf.
|
|
* @return number of bytes read or AVERROR
|
|
*/
|
|
int avio_read(AVIOContext *s, unsigned char *buf, int size);
|
|
|
|
/**
|
|
* Read size bytes from AVIOContext into buf. Unlike avio_read(), this is allowed
|
|
* to read fewer bytes than requested. The missing bytes can be read in the next
|
|
* call. This always tries to read at least 1 byte.
|
|
* Useful to reduce latency in certain cases.
|
|
* @return number of bytes read or AVERROR
|
|
*/
|
|
int avio_read_partial(AVIOContext *s, unsigned char *buf, int size);
|
|
|
|
/**
|
|
* @name Functions for reading from AVIOContext
|
|
* @{
|
|
*
|
|
* @note return 0 if EOF, so you cannot use it if EOF handling is
|
|
* necessary
|
|
*/
|
|
int avio_r8 (AVIOContext *s);
|
|
unsigned int avio_rl16(AVIOContext *s);
|
|
unsigned int avio_rl24(AVIOContext *s);
|
|
unsigned int avio_rl32(AVIOContext *s);
|
|
uint64_t avio_rl64(AVIOContext *s);
|
|
unsigned int avio_rb16(AVIOContext *s);
|
|
unsigned int avio_rb24(AVIOContext *s);
|
|
unsigned int avio_rb32(AVIOContext *s);
|
|
uint64_t avio_rb64(AVIOContext *s);
|
|
/**
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* Read a string from pb into buf. The reading will terminate when either
|
|
* a NULL character was encountered, maxlen bytes have been read, or nothing
|
|
* more can be read from pb. The result is guaranteed to be NULL-terminated, it
|
|
* will be truncated if buf is too small.
|
|
* Note that the string is not interpreted or validated in any way, it
|
|
* might get truncated in the middle of a sequence for multi-byte encodings.
|
|
*
|
|
* @return number of bytes read (is always <= maxlen).
|
|
* If reading ends on EOF or error, the return value will be one more than
|
|
* bytes actually read.
|
|
*/
|
|
int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
|
|
|
|
/**
|
|
* Read a UTF-16 string from pb and convert it to UTF-8.
|
|
* The reading will terminate when either a null or invalid character was
|
|
* encountered or maxlen bytes have been read.
|
|
* @return number of bytes read (is always <= maxlen)
|
|
*/
|
|
int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
|
|
int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
|
|
|
|
|
|
/**
|
|
* @name URL open modes
|
|
* The flags argument to avio_open must be one of the following
|
|
* constants, optionally ORed with other flags.
|
|
* @{
|
|
*/
|
|
#define AVIO_FLAG_READ 1 /**< read-only */
|
|
#define AVIO_FLAG_WRITE 2 /**< write-only */
|
|
#define AVIO_FLAG_READ_WRITE (AVIO_FLAG_READ|AVIO_FLAG_WRITE) /**< read-write pseudo flag */
|
|
/**
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* Use non-blocking mode.
|
|
* If this flag is set, operations on the context will return
|
|
* AVERROR(EAGAIN) if they can not be performed immediately.
|
|
* If this flag is not set, operations on the context will never return
|
|
* AVERROR(EAGAIN).
|
|
* Note that this flag does not affect the opening/connecting of the
|
|
* context. Connecting a protocol will always block if necessary (e.g. on
|
|
* network protocols) but never hang (e.g. on busy devices).
|
|
* Warning: non-blocking protocols is work-in-progress; this flag may be
|
|
* silently ignored.
|
|
*/
|
|
#define AVIO_FLAG_NONBLOCK 8
|
|
|
|
/**
|
|
* Use direct mode.
|
|
* avio_read and avio_write should if possible be satisfied directly
|
|
* instead of going through a buffer, and avio_seek will always
|
|
* call the underlying seek function directly.
|
|
*/
|
|
#define AVIO_FLAG_DIRECT 0x8000
|
|
|
|
/**
|
|
* Create and initialize a AVIOContext for accessing the
|
|
* resource indicated by url.
|
|
* @note When the resource indicated by url has been opened in
|
|
* read+write mode, the AVIOContext can be used only for writing.
|
|
*
|
|
* @param s Used to return the pointer to the created AVIOContext.
|
|
* In case of failure the pointed to value is set to NULL.
|
|
* @param url resource to access
|
|
* @param flags flags which control how the resource indicated by url
|
|
* is to be opened
|
|
* @return >= 0 in case of success, a negative value corresponding to an
|
|
* AVERROR code in case of failure
|
|
*/
|
|
int avio_open(AVIOContext **s, const char *url, int flags);
|
|
|
|
/**
|
|
* Create and initialize a AVIOContext for accessing the
|
|
* resource indicated by url.
|
|
* @note When the resource indicated by url has been opened in
|
|
* read+write mode, the AVIOContext can be used only for writing.
|
|
*
|
|
* @param s Used to return the pointer to the created AVIOContext.
|
|
* In case of failure the pointed to value is set to NULL.
|
|
* @param url resource to access
|
|
* @param flags flags which control how the resource indicated by url
|
|
* is to be opened
|
|
* @param int_cb an interrupt callback to be used at the protocols level
|
|
* @param options A dictionary filled with protocol-private options. On return
|
|
* this parameter will be destroyed and replaced with a dict containing options
|
|
* that were not found. May be NULL.
|
|
* @return >= 0 in case of success, a negative value corresponding to an
|
|
* AVERROR code in case of failure
|
|
*/
|
|
int avio_open2(AVIOContext **s, const char *url, int flags,
|
|
const AVIOInterruptCB *int_cb, AVDictionary **options);
|
|
|
|
/**
|
|
* Close the resource accessed by the AVIOContext s and free it.
|
|
* This function can only be used if s was opened by avio_open().
|
|
*
|
|
* The internal buffer is automatically flushed before closing the
|
|
* resource.
|
|
*
|
|
* @return 0 on success, an AVERROR < 0 on error.
|
|
* @see avio_closep
|
|
*/
|
|
int avio_close(AVIOContext *s);
|
|
|
|
/**
|
|
* Close the resource accessed by the AVIOContext *s, free it
|
|
* and set the pointer pointing to it to NULL.
|
|
* This function can only be used if s was opened by avio_open().
|
|
*
|
|
* The internal buffer is automatically flushed before closing the
|
|
* resource.
|
|
*
|
|
* @return 0 on success, an AVERROR < 0 on error.
|
|
* @see avio_close
|
|
*/
|
|
int avio_closep(AVIOContext **s);
|
|
|
|
|
|
/**
|
|
* Open a write only memory stream.
|
|
*
|
|
* @param s new IO context
|
|
* @return zero if no error.
|
|
*/
|
|
int avio_open_dyn_buf(AVIOContext **s);
|
|
|
|
/**
|
|
* Return the written size and a pointer to the buffer.
|
|
* The AVIOContext stream is left intact.
|
|
* The buffer must NOT be freed.
|
|
* No padding is added to the buffer.
|
|
*
|
|
* @param s IO context
|
|
* @param pbuffer pointer to a byte buffer
|
|
* @return the length of the byte buffer
|
|
*/
|
|
int avio_get_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
|
|
|
|
/**
|
|
* Return the written size and a pointer to the buffer. The buffer
|
|
* must be freed with av_free().
|
|
* Padding of AV_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
|
|
*
|
|
* @param s IO context
|
|
* @param pbuffer pointer to a byte buffer
|
|
* @return the length of the byte buffer
|
|
*/
|
|
int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
|
|
|
|
/**
|
|
* Iterate through names of available protocols.
|
|
*
|
|
* @param opaque A private pointer representing current protocol.
|
|
* It must be a pointer to NULL on first iteration and will
|
|
* be updated by successive calls to avio_enum_protocols.
|
|
* @param output If set to 1, iterate over output protocols,
|
|
* otherwise over input protocols.
|
|
*
|
|
* @return A static string containing the name of current protocol or NULL
|
|
*/
|
|
const char *avio_enum_protocols(void **opaque, int output);
|
|
|
|
/**
|
|
* Pause and resume playing - only meaningful if using a network streaming
|
|
* protocol (e.g. MMS).
|
|
*
|
|
* @param h IO context from which to call the read_pause function pointer
|
|
* @param pause 1 for pause, 0 for resume
|
|
*/
|
|
int avio_pause(AVIOContext *h, int pause);
|
|
|
|
/**
|
|
* Seek to a given timestamp relative to some component stream.
|
|
* Only meaningful if using a network streaming protocol (e.g. MMS.).
|
|
*
|
|
* @param h IO context from which to call the seek function pointers
|
|
* @param stream_index The stream index that the timestamp is relative to.
|
|
* If stream_index is (-1) the timestamp should be in AV_TIME_BASE
|
|
* units from the beginning of the presentation.
|
|
* If a stream_index >= 0 is used and the protocol does not support
|
|
* seeking based on component streams, the call will fail.
|
|
* @param timestamp timestamp in AVStream.time_base units
|
|
* or if there is no stream specified then in AV_TIME_BASE units.
|
|
* @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
|
|
* and AVSEEK_FLAG_ANY. The protocol may silently ignore
|
|
* AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
|
|
* fail if used and not supported.
|
|
* @return >= 0 on success
|
|
* @see AVInputFormat::read_seek
|
|
*/
|
|
int64_t avio_seek_time(AVIOContext *h, int stream_index,
|
|
int64_t timestamp, int flags);
|
|
|
|
/* Avoid a warning. The header can not be included because it breaks c++. */
|
|
struct AVBPrint;
|
|
|
|
/**
|
|
* Read contents of h into print buffer, up to max_size bytes, or up to EOF.
|
|
*
|
|
* @return 0 for success (max_size bytes read or EOF reached), negative error
|
|
* code otherwise
|
|
*/
|
|
int avio_read_to_bprint(AVIOContext *h, struct AVBPrint *pb, size_t max_size);
|
|
|
|
/**
|
|
* Accept and allocate a client context on a server context.
|
|
* @param s the server context
|
|
* @param c the client context, must be unallocated
|
|
* @return >= 0 on success or a negative value corresponding
|
|
* to an AVERROR on failure
|
|
*/
|
|
int avio_accept(AVIOContext *s, AVIOContext **c);
|
|
|
|
/**
|
|
* Perform one step of the protocol handshake to accept a new client.
|
|
* This function must be called on a client returned by avio_accept() before
|
|
* using it as a read/write context.
|
|
* It is separate from avio_accept() because it may block.
|
|
* A step of the handshake is defined by places where the application may
|
|
* decide to change the proceedings.
|
|
* For example, on a protocol with a request header and a reply header, each
|
|
* one can constitute a step because the application may use the parameters
|
|
* from the request to change parameters in the reply; or each individual
|
|
* chunk of the request can constitute a step.
|
|
* If the handshake is already finished, avio_handshake() does nothing and
|
|
* returns 0 immediately.
|
|
*
|
|
* @param c the client context to perform the handshake on
|
|
* @return 0 on a complete and successful handshake
|
|
* > 0 if the handshake progressed, but is not complete
|
|
* < 0 for an AVERROR code
|
|
*/
|
|
int avio_handshake(AVIOContext *c);
|
|
#endif /* AVFORMAT_AVIO_H */
|