I recently posted a question about Muxing MPEG-4 video into a MPEG-2 TS. I was
using quite an outdated version of libav so i am assuming that is the reason I
received no responses. I have rewritten the code to use release 0.8.
I am now able to write data to the MPEG-2 TS but when opening it with VLC
nothing appears despite the fact it knows there is a MPEG-4 video stream in
there. I then tried to inspect with ffmpeg as follows:
> ffmpeg.exe -i c:\bat.ts
ffmpeg version 0.8, Copyright (c) 2000-2011 the FFmpeg developers
built on Jul 23 2011 23:24:23 with gcc 3.4.4 (cygming special, gdc 0.12, using
dmd 0.125)
configuration: --enable-memalign-hack --enable-swscale --enable-w32threads --e
nable-shared --target-os=mingw32 --extra-cflags=-mno-cygwin --extra-libs=-mno-cy
gwin
libavutil 51. 9. 1 / 51. 9. 1
libavcodec 53. 7. 0 / 53. 7. 0
libavformat 53. 4. 0 / 53. 4. 0
libavdevice 53. 1. 1 / 53. 1. 1
libavfilter 2. 23. 0 / 2. 23. 0
libswscale 2. 0. 0 / 2. 0. 0
[mpeg4 @ 00ba80b0] hmm, seems the headers are not complete, trying to guess
time_increment_bits
[mpeg4 @ 00ba80b0] my guess is 5 bits ;)
Compiler did not align stack variables. Libavcodec has been miscompiled
and may be very slow or crash. This is not a bug in libavcodec,
but in the compiler. You may try recompiling using gcc >= 4.2.
Do not report crashes to FFmpeg developers.
[mpeg4 @ 00ba80b0] hmm, seems the headers are not complete, trying to guess time
_increment_bits
[mpeg4 @ 00ba80b0] my guess is 5 bits ;)
[mpeg4 @ 00ba80b0] looks like this file was encoded with
(divx4/(old)xvid/opendivx) -> forcing low_delay flag
[mpeg4 @ 00ba80b0] [IMGUTILS @ 0022e290] Picture size 0x0 is invalid
[mpeg4 @ 00ba80b0] get_buffer() failed (-1 0 0 00000000)
[mpeg4 @ 00ba80b0] [IMGUTILS @ 0022e290] Picture size 0x0 is invalid
[mpeg4 @ 00ba80b0] get_buffer() failed (-1 0 0 00000000)
[mpeg4 @ 00ba80b0] [IMGUTILS @ 0022e290] Picture size 0x0 is invalid
[mpeg4 @ 00ba80b0] get_buffer() failed (-1 0 0 00000000)
[mpeg4 @ 00ba80b0] [IMGUTILS @ 0022e290] Picture size 0x0 is invalid
[mpeg4 @ 00ba80b0] get_buffer() failed (-1 0 0 00000000)
[mpeg4 @ 00ba80b0] [IMGUTILS @ 0022e290] Picture size 0x0 is invalid
[mpeg4 @ 00ba80b0] get_buffer() failed (-1 0 0 00000000)
[mpeg4 @ 00ba80b0] [IMGUTILS @ 0022e290] Picture size 0x0 is invalid
[mpeg4 @ 00ba80b0] get_buffer() failed (-1 0 0 00000000)
[mpeg4 @ 00ba80b0] [IMGUTILS @ 0022e290] Picture size 0x0 is invalid
[mpeg4 @ 00ba80b0] get_buffer() failed (-1 0 0 00000000)
[mpegts @ 003ea370] Could not find codec parameters (Video: mpeg4, yuv420p)
[NULL @ 00ba80b0] start time is not set in av_estimate_timings_from_pts
c:\bat.ts: could not find codec parameters
any help would be greatly appreciated.
mark.
p.s. here's some code that i am using:
void initialize()
{
int framewidth = 704;
int frameheight = 480;
//av_register_all etc.
init();
// alloc the libavformat context and set the type to "MPEG-2 TS"
avformat_alloc_output_context2(&muxer, NULL, "mpegts", NULL);
if(!muxer) {
// error handling
}
// add the video stream to the muxer
addVideoStream(codec_name, framewidth, frameheight);
// not sure what this does? not documented in doxygen
av_dump_format(muxer, 0, "c:\\bat.ts", 1);
// open the video stream and allocate default buffers
openVideoStream();
// allocate the buffer to write the destination packets to
avio_open(&muxer->pb, "c:\\bat.ts", URL_WRONLY);
// set the parameters for the muxer
av_write_header(muxer);
}
void addVideoStream(std::string codec_name, int width, int height)
{
// add a new stream to the container
vstream = av_new_stream(muxer, 0);
if (!vstream) {
// error handling
}
// set a handle to the stream's codec ("the codec context")
codecContext = vstream->codec;
// set the stream type to video and specify the codec
codecContext->codec_type = AVMEDIA_TYPE_VIDEO;
if ( "H.264" == codec_name)
{
codecContext->codec_id = CODEC_ID_H264;
}
else if ( "MPEG-4" == codec_name)
{
codecContext->codec_id = CODEC_ID_MPEG4;
}
else // "MPEG2"
{
codecContext->codec_id = CODEC_ID_MPEG2VIDEO;
}
// fill in sample parameters
codecContext->global_quality = FF_QP2LAMBDA;
codecContext->bit_rate = 200000;
// resolution must be a multiple of two
codecContext->width = width;
codecContext->height = height;
// set additional properties of the video stream
codecContext->time_base.den = 25;
codecContext->time_base.num = 1;
codecContext->gop_size = 12; /* emit one intra frame every twelve
frames at most */
codecContext->pix_fmt = PIX_FMT_YUV420P;
codecContext->flags |= CODEC_FLAG_GLOBAL_HEADER;
codecContext->flags |= CODEC_FLAG_QSCALE;
codecContext->max_b_frames = 0;
// some formats want stream headers to be separate
if (muxer->oformat->flags & AVFMT_GLOBALHEADER)
codecContext->flags |= CODEC_FLAG_GLOBAL_HEADER;
}
void openVideoStream()
{
// get the encoder for the codec
vcodec = avcodec_find_encoder(codecContext->codec_id);
// attempt to open the encoder
if (avcodec_open(codecContext, vcodec) < 0)
{
// error handling
}
video_outbuf_size = 200000; // not sure how this number was chosen? it
seems to be the accepted value though
fTo = (uint8_t *) malloc(video_outbuf_size);
video_outbuf = (uint8_t *) malloc(video_outbuf_size);
}
void doGetNextFrame(AVFrame* rgbimage)
{
AVFrame *tmp_picture = avcodec_alloc_frame();
unsigned int size = avpicture_get_size(codecContext->pix_fmt,
codecContext->width, codecContext->height);
uint8_t *picture_buf = (uint8_t *) malloc(size);
int fillres = avpicture_fill((AVPicture *)tmp_picture, picture_buf,
codecContext->pix_fmt, codecContext->width, codecContext->height);
int out_size = 0;
// color convert the image... swsConvert is a company wrapper
for sws_scale
bool success = swsConvert(tmp_picture, rgbimage,
codecContext->pix_fmt);
tmp_picture->quality = FF_QP2LAMBDA;
// encode the stream into video_outbuf
// returns a negative value on error
out_size = avcodec_encode_video(codecContext, video_outbuf,
video_outbuf_size, tmp_picture);
mFrameQueue->pop_front();
if (out_size > 0)
{
// create an AVPacket using the encoded imagery
AVPacket pkt;
av_init_packet(&pkt);
pkt.data = video_outbuf;
pkt.size = out_size;
pkt.stream_index = vstream->index;
pkt.pts= av_rescale_q(codecContext->coded_frame->pts,
codecContext->time_base, vstream->time_base);
pkt.flags |= AV_PKT_FLAG_KEY;
// write the frame
if (av__write_frame(muxer, &pkt) < 0)
{
// error handling
}
av_free_packet(&pkt);
av_free(tmp_picture);
delete[] picture_buf;
}
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