vgmstream/src/meta/ffmpeg.c
bnnm 0faa3286aa Don't manually check framesRead and rely on FFmpeg's EOFs
FFmpeg's duration isn't always reliable (ie. bad headers) and the
decoder detects EOFs already, extra decoding attempts should be ignored.
This way vgmstream can use other values without modifying
ffmpeg_codec_data's state.
2016-12-03 11:42:38 +01:00

486 lines
14 KiB
C

#include "../vgmstream.h"
#include "meta.h"
#include "../util.h"
#ifdef VGM_USE_FFMPEG
/* internal sizes, can be any value */
#define FFMPEG_DEFAULT_BLOCK_SIZE 2048
#define FFMPEG_DEFAULT_IO_BUFFER_SIZE 128 * 1024
static int init_seek(ffmpeg_codec_data * data);
static volatile int g_ffmpeg_initialized = 0;
/*
* Global FFmpeg init
*/
static void g_init_ffmpeg()
{
if (g_ffmpeg_initialized == 1)
{
while (g_ffmpeg_initialized < 2);
}
else if (g_ffmpeg_initialized == 0)
{
g_ffmpeg_initialized = 1;
av_log_set_flags(AV_LOG_SKIP_REPEATED);
av_log_set_level(AV_LOG_ERROR);
av_register_all();
g_ffmpeg_initialized = 2;
}
}
/**
* Generic init FFmpeg and vgmstream for any file supported by FFmpeg.
* Always called by vgmstream when trying to identify the file type (if the player allows it).
*/
VGMSTREAM * init_vgmstream_ffmpeg(STREAMFILE *streamFile) {
return init_vgmstream_ffmpeg_offset( streamFile, 0, streamFile->get_size(streamFile) );
}
VGMSTREAM * init_vgmstream_ffmpeg_offset(STREAMFILE *streamFile, uint64_t start, uint64_t size) {
VGMSTREAM *vgmstream = NULL;
ffmpeg_codec_data *data = init_ffmpeg_offset(streamFile, start, size);
if (!data) return NULL;
vgmstream = allocate_vgmstream(data->channels, 0);
if (!vgmstream) goto fail;
vgmstream->loop_flag = 0;
vgmstream->codec_data = data;
vgmstream->channels = data->channels;
vgmstream->sample_rate = data->sampleRate;
vgmstream->num_samples = data->totalFrames;
vgmstream->coding_type = coding_FFmpeg;
vgmstream->layout_type = layout_none;
vgmstream->meta_type = meta_FFmpeg;
/* this may happen for some streams */
if (vgmstream->num_samples <= 0)
goto fail;
return vgmstream;
fail:
free_ffmpeg(data);
if (vgmstream) {
vgmstream->codec_data = NULL;
close_vgmstream(vgmstream);
}
return NULL;
}
/**
* AVIO callback: read stream, skipping external headers if needed
*/
static int ffmpeg_read(void *opaque, uint8_t *buf, int buf_size)
{
ffmpeg_codec_data *data = (ffmpeg_codec_data *) opaque;
uint64_t offset = data->offset;
int max_to_copy = 0;
int ret;
if (data->header_insert_block) {
if (offset < data->header_size) {
max_to_copy = (int)(data->header_size - offset);
if (max_to_copy > buf_size) {
max_to_copy = buf_size;
}
memcpy(buf, data->header_insert_block + offset, max_to_copy);
buf += max_to_copy;
buf_size -= max_to_copy;
offset += max_to_copy;
if (!buf_size) {
data->offset = offset;
return max_to_copy;
}
}
offset -= data->header_size;
}
ret = read_streamfile(buf, offset + data->start, buf_size, data->streamfile);
if (ret > 0) {
offset += ret;
if (data->header_insert_block) {
ret += max_to_copy;
}
}
if (data->header_insert_block) {
offset += data->header_size;
}
data->offset = offset;
return ret;
}
/**
* AVIO callback: write stream not needed
*/
static int ffmpeg_write(void *opaque, uint8_t *buf, int buf_size)
{
return -1;
}
/**
* AVIO callback: seek stream, skipping external headers if needed
*/
static int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence)
{
ffmpeg_codec_data *data = (ffmpeg_codec_data *) opaque;
if (whence & AVSEEK_SIZE) {
return data->size + data->header_size;
}
whence &= ~(AVSEEK_SIZE | AVSEEK_FORCE);
/* false offsets, on reads data->start will be added */
switch (whence) {
case SEEK_SET:
break;
case SEEK_CUR:
offset += data->offset;
break;
case SEEK_END:
offset += data->size;
if (data->header_insert_block)
offset += data->header_size;
break;
}
if (offset > data->size + data->header_size)
offset = data->size + data->header_size;
return data->offset = offset;
}
/**
* Manually init FFmpeg only, from an offset.
* Can be used if the stream has an extra header over data recognized by FFmpeg.
*/
ffmpeg_codec_data * init_ffmpeg_offset(STREAMFILE *streamFile, uint64_t start, uint64_t size) {
return init_ffmpeg_faux_riff(streamFile, -1, start, size, 0);
}
/**
* Manually init FFmpeg only, from an offset / fake RIFF.
* Can insert a fake RIFF header, to trick FFmpeg into demuxing/decoding the stream.
*/
ffmpeg_codec_data * init_ffmpeg_faux_riff(STREAMFILE *streamFile, int64_t fmt_offset, uint64_t start, uint64_t size, int big_endian) {
char filename[PATH_LIMIT];
ffmpeg_codec_data * data;
int errcode, i;
int streamIndex;
AVStream *stream;
AVCodecParameters *codecPar;
AVRational tb;
/* basic setup */
g_init_ffmpeg();
data = ( ffmpeg_codec_data * ) calloc(1, sizeof(ffmpeg_codec_data));
if (!data) return NULL;
streamFile->get_name( streamFile, filename, sizeof(filename) );
data->streamfile = streamFile->open(streamFile, filename, STREAMFILE_DEFAULT_BUFFER_SIZE);
if (!data->streamfile) goto fail;
data->start = start;
data->size = size;
/* insert fake RIFF header to trick FFmpeg into demuxing/decoding the stream */
if (fmt_offset > 0) {
int max_header_size = (int)(start - fmt_offset);
uint8_t *p;
if (max_header_size < 18) goto fail;
data->header_insert_block = p = av_malloc(max_header_size + 8 + 4 + 8 + 8);
if (!data->header_insert_block) goto fail;
if (read_streamfile(p + 8 + 4 + 8, fmt_offset, max_header_size, streamFile) != max_header_size) goto fail;
if (big_endian) {
p += 8 + 4 + 8;
put_16bitLE(p, get_16bitBE(p));
put_16bitLE(p + 2, get_16bitBE(p + 2));
put_32bitLE(p + 4, get_32bitBE(p + 4));
put_32bitLE(p + 8, get_32bitBE(p + 8));
put_16bitLE(p + 12, get_16bitBE(p + 12));
put_16bitLE(p + 14, get_16bitBE(p + 14));
put_16bitLE(p + 16, get_16bitBE(p + 16));
p -= 8 + 4 + 8;
}
data->header_size = 8 + 4 + 8 + 8 + 18 + get_16bitLE(p + 8 + 4 + 8 + 16);
// Meh, dunno how to handle swapping the extra data
// FFmpeg doesn't need most of this data anyway
if ((unsigned)(get_16bitLE(p + 8 + 4 + 8) - 0x165) < 2)
memset(p + 8 + 4 + 8 + 18, 0, 34);
// Fill out the RIFF structure
memcpy(p, "RIFF", 4);
put_32bitLE(p + 4, data->header_size + size - 8);
memcpy(p + 8, "WAVE", 4);
memcpy(p + 12, "fmt ", 4);
put_32bitLE(p + 16, 18 + get_16bitLE(p + 8 + 4 + 8 + 16));
memcpy(p + data->header_size - 8, "data", 4);
put_32bitLE(p + data->header_size - 4, size);
}
/* setup IO, attempt to autodetect format and gather some info */
data->buffer = av_malloc(FFMPEG_DEFAULT_IO_BUFFER_SIZE);
if (!data->buffer) goto fail;
data->ioCtx = avio_alloc_context(data->buffer, FFMPEG_DEFAULT_IO_BUFFER_SIZE, 0, data, ffmpeg_read, ffmpeg_write, ffmpeg_seek);
if (!data->ioCtx) goto fail;
data->formatCtx = avformat_alloc_context();
if (!data->formatCtx) goto fail;
data->formatCtx->pb = data->ioCtx;
if ((errcode = avformat_open_input(&data->formatCtx, "", NULL, NULL)) < 0) goto fail; /* autodetect */
if ((errcode = avformat_find_stream_info(data->formatCtx, NULL)) < 0) goto fail;
/* find valid audio stream inside */
streamIndex = -1;
for (i = 0; i < data->formatCtx->nb_streams; ++i) {
stream = data->formatCtx->streams[i];
codecPar = stream->codecpar;
if (streamIndex < 0 && codecPar->codec_type == AVMEDIA_TYPE_AUDIO) {
streamIndex = i; /* select first audio stream found */
} else {
stream->discard = AVDISCARD_ALL; /* disable demuxing unneded streams */
}
}
if (streamIndex < 0) goto fail;
data->streamIndex = streamIndex;
stream = data->formatCtx->streams[streamIndex];
/* prepare codec and frame/packet buffers */
data->codecCtx = avcodec_alloc_context3(NULL);
if (!data->codecCtx) goto fail;
if ((errcode = avcodec_parameters_to_context(data->codecCtx, codecPar)) < 0) goto fail;
av_codec_set_pkt_timebase(data->codecCtx, stream->time_base);
data->codec = avcodec_find_decoder(data->codecCtx->codec_id);
if (!data->codec) goto fail;
if ((errcode = avcodec_open2(data->codecCtx, data->codec, NULL)) < 0) goto fail;
data->lastDecodedFrame = av_frame_alloc();
if (!data->lastDecodedFrame) goto fail;
av_frame_unref(data->lastDecodedFrame);
data->lastReadPacket = malloc(sizeof(AVPacket));
if (!data->lastReadPacket) goto fail;
av_new_packet(data->lastReadPacket, 0);
data->readNextPacket = 1;
data->bytesConsumedFromDecodedFrame = INT_MAX;
/* other setup */
data->sampleRate = data->codecCtx->sample_rate;
data->channels = data->codecCtx->channels;
data->floatingPoint = 0;
switch (data->codecCtx->sample_fmt) {
case AV_SAMPLE_FMT_U8:
case AV_SAMPLE_FMT_U8P:
data->bitsPerSample = 8;
break;
case AV_SAMPLE_FMT_S16:
case AV_SAMPLE_FMT_S16P:
data->bitsPerSample = 16;
break;
case AV_SAMPLE_FMT_S32:
case AV_SAMPLE_FMT_S32P:
data->bitsPerSample = 32;
break;
case AV_SAMPLE_FMT_FLT:
case AV_SAMPLE_FMT_FLTP:
data->bitsPerSample = 32;
data->floatingPoint = 1;
break;
case AV_SAMPLE_FMT_DBL:
case AV_SAMPLE_FMT_DBLP:
data->bitsPerSample = 64;
data->floatingPoint = 1;
break;
default:
goto fail;
}
data->bitrate = (int)(data->codecCtx->bit_rate);
data->endOfStream = 0;
data->endOfAudio = 0;
/* try to guess frames/samples (duration isn't always set) */
tb.num = 1; tb.den = data->codecCtx->sample_rate;
data->totalFrames = av_rescale_q(stream->duration, stream->time_base, tb);
if (data->totalFrames < 0)
data->totalFrames = 0; /* caller must consider this */
/* setup decode buffer */
data->samplesPerBlock = FFMPEG_DEFAULT_BLOCK_SIZE;
data->sampleBuffer = av_malloc( data->samplesPerBlock * (data->bitsPerSample / 8) * data->channels );
if (!data->sampleBuffer)
goto fail;
/* setup decent seeking for faulty formats */
errcode = init_seek(data);
if (errcode < 0) goto fail;
return data;
fail:
free_ffmpeg(data);
return NULL;
}
/**
* Special patching for FFmpeg's buggy seek code.
*
* To seek with avformat_seek_file/av_seek_frame, FFmpeg's demuxers can implement read_seek2 (newest API)
* or read_seek (older API), with various search modes. If none are available it will use seek_frame_generic,
* which manually reads frame by frame until the selected timestamp. However, the prev frame will be consumed
* (so after seeking to 0 next av_read_frame will actually give the second frame and so on).
*
* Fortunately seek_frame_generic can use an index to find the correct position. This function reads the
* first frame/packet and sets up index to timestamp 0. This ensures faulty demuxers will seek to 0 correctly.
* Some formats may not seek to 0 even with this, though.
*/
static int init_seek(ffmpeg_codec_data * data) {
int ret, ts_index, found_first = 0;
int64_t ts = 0;
int64_t pos; /* offset */
int size; /* coded size */
int distance = 0; /* always? */
AVStream * stream;
AVPacket * pkt;
stream = data->formatCtx->streams[data->streamIndex];
pkt = data->lastReadPacket;
/* read_seek shouldn't need this index, but direct access to FFmpeg's internals is no good */
/* if (data->formatCtx->iformat->read_seek || data->formatCtx->iformat->read_seek2)
return 0; */
/* some formats already have a proper index (e.g. M4A) */
ts_index = av_index_search_timestamp(stream, ts, AVSEEK_FLAG_ANY);
if (ts_index>=0)
goto test_seek;
/* find the first + second packets to get pos/size */
while (1) {
av_packet_unref(pkt);
ret = av_read_frame(data->formatCtx, pkt);
if (ret < 0)
goto fail;
if (pkt->stream_index != data->streamIndex)
continue; /* ignore non-selected streams */
if (!found_first) { /* first found */
found_first = 1;
pos = pkt->pos;
continue;
} else { /* second found */
size = pkt->pos - pos; /* coded, pkt->size is decoded size */
break;
}
}
/* add index 0 */
ret = av_add_index_entry(stream, pos, ts, size, distance, AVINDEX_KEYFRAME);
if ( ret < 0 )
return ret;
test_seek:
/* seek to 0 test / move back to beginning, since we just consumed packets */
ret = avformat_seek_file(data->formatCtx, data->streamIndex, ts, ts, ts, AVSEEK_FLAG_ANY);
if ( ret < 0 )
return ret; /* we can't even reset_vgmstream the file */
avcodec_flush_buffers(data->codecCtx);
return 0;
fail:
return -1;
}
void free_ffmpeg(ffmpeg_codec_data *data) {
if (data->lastReadPacket) {
av_packet_unref(data->lastReadPacket);
free(data->lastReadPacket);
data->lastReadPacket = NULL;
}
if (data->lastDecodedFrame) {
av_free(data->lastDecodedFrame);
data->lastDecodedFrame = NULL;
}
if (data->codecCtx) {
avcodec_close(data->codecCtx);
avcodec_free_context(&(data->codecCtx));
data->codecCtx = NULL;
}
if (data->formatCtx) {
avformat_close_input(&(data->formatCtx));
data->formatCtx = NULL;
}
if (data->ioCtx) {
// buffer passed in is occasionally freed and replaced.
// the replacement must be freed as well.
data->buffer = data->ioCtx->buffer;
av_free(data->ioCtx);
data->ioCtx = NULL;
}
if (data->buffer) {
av_free(data->buffer);
data->buffer = NULL;
}
if (data->sampleBuffer) {
av_free(data->sampleBuffer);
data->sampleBuffer = NULL;
}
if (data->header_insert_block) {
av_free(data->header_insert_block);
data->header_insert_block = NULL;
}
if (data->streamfile) {
close_streamfile(data->streamfile);
data->streamfile = NULL;
}
free(data);
}
#endif