From 0103f449d0d6a811daea96114d47885ebfc5a426 Mon Sep 17 00:00:00 2001
From: bnnm <bananaman255@gmail.com>
Date: Sat, 19 Aug 2017 10:28:28 +0200
Subject: [PATCH] Pass stream_index to FFmpeg manually for flexibility

---
 src/coding/coding.h         |  2 ++
 src/coding/ffmpeg_decoder.c | 22 +++++++++++++---------
 src/meta/bik.c              |  3 ++-
 3 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/coding/coding.h b/src/coding/coding.h
index baf35d17..da848242 100644
--- a/src/coding/coding.h
+++ b/src/coding/coding.h
@@ -198,7 +198,9 @@ void free_at3plus(maiatrac3plus_codec_data *data);
 #ifdef VGM_USE_FFMPEG
 /* ffmpeg_decoder */
 ffmpeg_codec_data * init_ffmpeg_offset(STREAMFILE *streamFile, uint64_t start, uint64_t size);
+ffmpeg_codec_data * init_ffmpeg_offset_index(STREAMFILE *streamFile, uint64_t start, uint64_t size, int stream_index);
 ffmpeg_codec_data * init_ffmpeg_header_offset(STREAMFILE *streamFile, uint8_t * header, uint64_t header_size, uint64_t start, uint64_t size);
+ffmpeg_codec_data * init_ffmpeg_header_offset_index(STREAMFILE *streamFile, uint8_t * header, uint64_t header_size, uint64_t start, uint64_t size, int stream_index);
 
 void decode_ffmpeg(VGMSTREAM *stream, sample * outbuf, int32_t samples_to_do, int channels);
 void reset_ffmpeg(VGMSTREAM *vgmstream);
diff --git a/src/coding/ffmpeg_decoder.c b/src/coding/ffmpeg_decoder.c
index 6838a3fc..ae31a4be 100644
--- a/src/coding/ffmpeg_decoder.c
+++ b/src/coding/ffmpeg_decoder.c
@@ -272,13 +272,16 @@ static int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 /* MAIN INIT/DECODER                            */
 /* ******************************************** */
 
-/**
- * Manually init FFmpeg, from an offset.
- * Used if the stream has internal data recognized by FFmpeg.
- */
 ffmpeg_codec_data * init_ffmpeg_offset(STREAMFILE *streamFile, uint64_t start, uint64_t size) {
-    return init_ffmpeg_header_offset(streamFile, NULL, 0, start, size);
+    return init_ffmpeg_header_offset_index(streamFile, NULL,0, start,size, 0);
 }
+ffmpeg_codec_data * init_ffmpeg_offset_index(STREAMFILE *streamFile, uint64_t start, uint64_t size, int stream_index) {
+    return init_ffmpeg_header_offset_index(streamFile, NULL,0, start,size, stream_index);
+}
+ffmpeg_codec_data * init_ffmpeg_header_offset(STREAMFILE *streamFile, uint8_t * header, uint64_t header_size, uint64_t start, uint64_t size) {
+    return init_ffmpeg_header_offset_index(streamFile, header,header_size, start,size, 0);
+}
+
 
 /**
  * Manually init FFmpeg, from a fake header / offset.
@@ -286,8 +289,10 @@ ffmpeg_codec_data * init_ffmpeg_offset(STREAMFILE *streamFile, uint64_t start, u
  * Takes a fake header, to trick FFmpeg into demuxing/decoding the stream.
  * This header will be seamlessly inserted before 'start' offset, and total filesize will be 'header_size' + 'size'.
  * The header buffer will be copied and memory-managed internally.
+ * NULL header can used given if the stream has internal data recognized by FFmpeg at offset.
+ * Stream index can be passed to FFmpeg, if the format has multiple streams (1=first).
  */
-ffmpeg_codec_data * init_ffmpeg_header_offset(STREAMFILE *streamFile, uint8_t * header, uint64_t header_size, uint64_t start, uint64_t size) {
+ffmpeg_codec_data * init_ffmpeg_header_offset_index(STREAMFILE *streamFile, uint8_t * header, uint64_t header_size, uint64_t start, uint64_t size, int stream_index) {
     char filename[PATH_LIMIT];
     ffmpeg_codec_data * data;
     int errcode, i;
@@ -349,8 +354,7 @@ ffmpeg_codec_data * init_ffmpeg_header_offset(STREAMFILE *streamFile, uint8_t *
             streamCount++;
 
             /* select Nth audio stream if specified, or first one */
-            if (streamIndex < 0 ||
-                    (streamFile->stream_index > 0 && streamCount == streamFile->stream_index)) {
+            if (streamIndex < 0 || (stream_index > 0 && streamCount == stream_index)) {
                 codecPar = stream->codecpar;
                 streamIndex = i;
             }
@@ -359,7 +363,7 @@ ffmpeg_codec_data * init_ffmpeg_header_offset(STREAMFILE *streamFile, uint8_t *
         if (i != streamIndex)
             stream->discard = AVDISCARD_ALL; /* disable demuxing for other streams */
     }
-    if (streamCount < streamFile->stream_index) goto fail;
+    if (streamCount < stream_index) goto fail;
     if (streamIndex < 0 || !codecPar) goto fail;
 
     data->streamIndex = streamIndex;
diff --git a/src/meta/bik.c b/src/meta/bik.c
index d178508a..20ca20ff 100644
--- a/src/meta/bik.c
+++ b/src/meta/bik.c
@@ -8,6 +8,7 @@ static int bink_get_info(STREAMFILE *streamFile, int * out_total_streams, int *
 VGMSTREAM * init_vgmstream_bik(STREAMFILE *streamFile) {
     VGMSTREAM * vgmstream = NULL;
     int channel_count = 0, loop_flag = 0, sample_rate = 0, num_samples = 0, total_streams = 0;
+    int stream_index = streamFile->stream_index;
 
 
     /* check extension, case insensitive (bika = manually demuxed audio) */
@@ -34,7 +35,7 @@ VGMSTREAM * init_vgmstream_bik(STREAMFILE *streamFile) {
 #ifdef VGM_USE_FFMPEG
     {
         /* init_FFmpeg uses streamFile->stream_index internally, if specified */
-        vgmstream->codec_data = init_ffmpeg_offset(streamFile, 0x0, get_streamfile_size(streamFile));
+        vgmstream->codec_data = init_ffmpeg_offset_index(streamFile, 0x0, get_streamfile_size(streamFile), stream_index);
         if (!vgmstream->codec_data) goto fail;
         vgmstream->coding_type = coding_FFmpeg;
     }