I found a discrepancy in output_example.c and my version below. I am
trying to call av_write_frame() after a avcodec_decode_video(),
output_example.c does this after an encode. So I tried to mux to a
file on the encode side and at least it works without crashing. Is it
not possible to mux after a decode? What is it that is different. All
I need is the encoded data and size right? There is obviously
something different in AVCodecContext after a decode and after an
encode. Does anyone know what needs to be set in order to call
av_write_frame?
-Jordan
Quoting Jordan Dressman <[EMAIL PROTECTED]>:
> I am following the output_example.c example to try to save encoded
> mpeg2video data in a mpeg2 PS format. When I call av_write_frame() I
> get integer division by 0 call stack > _av_guess_image2_codec() +
> 0x1c732 bytes. I must be missing some initialization.
>
> This is the basics of my code:
>
> AVFormatContext *format;
> AVOutputFormat *mpeg2dvd_muxer;
> AVCodecContext *c;
>
> init(){
> format->filename = someFileName;
> mpeg2dvd_muxer = guess_format("dvd", NULL, "video/mpeg");
> format->oformat = mpeg2dvd_muxer;
> video_st = av_new_stream(format, 0);
> url_fopen(&format->pb, format->filename, URL_WRONLY);
> av_write_header(format);
> video_st->codec = c;
> }
>
> ...
> len = avcodec_decode_video(c, frameYUV, &gotPicture, inbufPtr, size);
> if(len > 0)
> {
> AVPacket pkt;
> av_init_packet(&pkt);
>
> if (c->coded_frame->pts != AV_NOPTS_VALUE)
> pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base,
> video_st->time_base);
> if(c->coded_frame->key_frame)
> pkt.flags |= PKT_FLAG_KEY;
> pkt.stream_index = video_st->index;
> pkt.data = inbufPtr;
> pkt.size = size;
> av_write_frame(format, &pkt); //crashes integer division by 0 in
> av_guess_image2_codec
> }
> ...
>
>
>
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