After starting this question Extracting the h264 part of a video file (demuxing) I was actually able to figure out that,
- When I reverted to an older version of FFMPEG (avcodec-55.dll) as against the avcodec-57.dll I was using earlier, the code worked perfectly without any error and the resultant h264 file played with ffplay.
- When I tracked my output when using the avcodec-57.dll version of FFMPEG (most recent version), there was actually an error
"Using AVStream.codec.time_base as a timebase hint to the muxer is deprecated. Set AVStream.time_base instead"after the callavformat_write_header(ofmt_ctx_v, NULL)and another one after the call toavformat_write_header(ofmt_ctx_a, NULL). The program continued executing, the audio was fine but the .h264 file wasn't.
The output
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==============Input Video=============
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'sample.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
title : 10153755968775490
encoder : Lavf57.19.100
Duration: 00:01:07.27, start: 0.020021, bitrate: 1058 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 400x224 [
SAR 199:200 DAR 199:112], 927 kb/s, 15 fps, 15 tbr, 15360 tbn, 30 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(eng): Audio: mp3 (mp4a / 0x6134706D), 48000 Hz, stereo, s16p, 12
8 kb/s (default)
Metadata:
handler_name : SoundHandler
==============Output Video============
Output #0, h264, to 'sample.h264':
Stream #0:0: Video: h264 (High), yuv420p, 400x224 [SAR 199:200 DAR 199:112],
q=2-31, 927 kb/s, 30 tbc
==============Output Audio============
Output #0, mp3, to 'sample.mp3':
Stream #0:0: Audio: mp3, 48000 Hz, stereo, s16p, 128 kb/s
======================================
[h264 @ 00a3ee20] Using AVStream.codec.time_base as a timebase hint to the muxer
is deprecated. Set AVStream.time_base instead.
[mp3 @ 00a4fec0] Using AVStream.codec.time_base as a timebase hint to the muxer
is deprecated. Set AVStream.time_base instead.
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The code
#include <stdio.h>
#define __STDC_CONSTANT_MACROS
extern "C"
{
#include "libavformat/avformat.h"
}
#define USE_H264BSF 1
int main()
{
AVOutputFormat *ofmt_a = NULL,*ofmt_v = NULL;
AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx_a = NULL, *ofmt_ctx_v = NULL;
AVPacket pkt;
int ret, i;
int videoindex=-1,audioindex=-1;
int frame_index=0;
const char *in_filename = "sample.mp4";
const char *out_filename_v = "sample.h264";
const char *out_filename_a = "sample.mp3";
av_register_all();
//Input
if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
printf( "Could not open input file.");
goto end;
}
if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
printf( "Failed to retrieve input stream information");
goto end;
}
system("pause");
//Output
avformat_alloc_output_context2(&ofmt_ctx_v, NULL, NULL, out_filename_v);
if (!ofmt_ctx_v) {
printf( "Could not create output context\n");
ret = AVERROR_UNKNOWN;
goto end;
}
ofmt_v = ofmt_ctx_v->oformat;
system("pause");
avformat_alloc_output_context2(&ofmt_ctx_a, NULL, NULL, out_filename_a);
if (!ofmt_ctx_a) {
printf( "Could not create output context\n");
ret = AVERROR_UNKNOWN;
goto end;
}
ofmt_a = ofmt_ctx_a->oformat;
system("pause");
for (i = 0; i < ifmt_ctx->nb_streams; i++) {
//Create output AVStream according to input AVStream
AVFormatContext *ofmt_ctx;
AVStream *in_stream = ifmt_ctx->streams[i];
AVStream *out_stream = NULL;
if(ifmt_ctx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){
videoindex=i;
out_stream=avformat_new_stream(ofmt_ctx_v, in_stream->codec->codec);
ofmt_ctx=ofmt_ctx_v;
}else if(ifmt_ctx->streams[i]->codec->codec_type==AVMEDIA_TYPE_AUDIO){
audioindex=i;
out_stream=avformat_new_stream(ofmt_ctx_a, in_stream->codec->codec);
ofmt_ctx=ofmt_ctx_a;
}else{
break;
}
if (!out_stream) {
printf( "Failed allocating output stream\n");
ret = AVERROR_UNKNOWN;
goto end;
}
//Copy the settings of AVCodecContext
if (avcodec_copy_context(out_stream->codec, in_stream->codec) < 0) {
printf( "Failed to copy context from input to output stream codec context\n");
goto end;
}
out_stream->codec->codec_tag = 0;
if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
}
system("pause");
//Dump Format------------------
printf("\n==============Input Video=============\n");
av_dump_format(ifmt_ctx, 0, in_filename, 0);
printf("\n==============Output Video============\n");
av_dump_format(ofmt_ctx_v, 0, out_filename_v, 1);
printf("\n==============Output Audio============\n");
av_dump_format(ofmt_ctx_a, 0, out_filename_a, 1);
printf("\n======================================\n");
//Open output file
if (!(ofmt_v->flags & AVFMT_NOFILE)) {
if (avio_open(&ofmt_ctx_v->pb, out_filename_v, AVIO_FLAG_WRITE) < 0) {
printf( "Could not open output file '%s'", out_filename_v);
goto end;
}
}
if (!(ofmt_a->flags & AVFMT_NOFILE)) {
if (avio_open(&ofmt_ctx_a->pb, out_filename_a, AVIO_FLAG_WRITE) < 0) {
printf( "Could not open output file '%s'", out_filename_a);
goto end;
}
}
//Write file header
if (avformat_write_header(ofmt_ctx_v, NULL) < 0) {
printf( "Error occurred when opening video output file\n");
goto end;
}
if (avformat_write_header(ofmt_ctx_a, NULL) < 0) {
printf( "Error occurred when opening audio output file\n");
goto end;
}
system("pause");
#if USE_H264BSF
AVBitStreamFilterContext* h264bsfc = av_bitstream_filter_init("h264_mp4toannexb");
#endif
while (1) {
AVFormatContext *ofmt_ctx;
AVStream *in_stream, *out_stream;
//Get an AVPacket
if (av_read_frame(ifmt_ctx, &pkt) < 0)
break;
in_stream = ifmt_ctx->streams[pkt.stream_index];
if(pkt.stream_index==videoindex){
out_stream = ofmt_ctx_v->streams[0];
ofmt_ctx=ofmt_ctx_v;
#if USE_H264BSF
av_bitstream_filter_filter(h264bsfc, in_stream->codec, NULL, &pkt.data, &pkt.size, pkt.data, pkt.size, 0);
#endif
printf("Write Video Packet. size:%d\tpts:%lld\n",pkt.size,pkt.pts);
}else if(pkt.stream_index==audioindex){
out_stream = ofmt_ctx_a->streams[0];
ofmt_ctx=ofmt_ctx_a;
printf("Write Audio Packet. size:%d\tpts:%lld\n",pkt.size,pkt.pts);
}else{
continue;
}
//Convert PTS/DTS
pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
pkt.pos = -1;
pkt.stream_index=0;
//Write
if (av_interleaved_write_frame(ofmt_ctx, &pkt) < 0) {
printf( "Error muxing packet\n");
break;
}
//printf("Write %8d frames to output file\n", frame_index);
av_free_packet(&pkt);
frame_index++;
}
system("pause");
#if USE_H264BSF
av_bitstream_filter_close(h264bsfc);
#endif
//Write file trailer
av_write_trailer(ofmt_ctx_a);
av_write_trailer(ofmt_ctx_v);
end:
avformat_close_input(&ifmt_ctx);
/* close output */
if (ofmt_ctx_a && !(ofmt_a->flags & AVFMT_NOFILE))
avio_close(ofmt_ctx_a->pb);
if (ofmt_ctx_v && !(ofmt_v->flags & AVFMT_NOFILE))
avio_close(ofmt_ctx_v->pb);
avformat_free_context(ofmt_ctx_a);
avformat_free_context(ofmt_ctx_v);
system("pause");
if (ret < 0 && ret != AVERROR_EOF) {
printf( "Error occurred.\n");
return -1;
}
return 0;
}
EDIT 1
After reading through http://lists.libav.org/pipermail/libav-devel/2014-June/060048.html, I figured what was causing the "Using AVStream.codec.time_base as a timebase hint to the muxer is deprecated. Set AVStream.time_base instead". I fixed it by adding out_stream->time_base = in_stream->time_base; before the call to avformat_write_header. The code now runs without any error! The h264 file created with the old FFMPEG (avcodec-55.dll) works fine while that created by the recent avcodec-57.dll is still invalid.
