Hi Michael, I did what you've suggested and found out how to encode directly from a live source and it works indeed. I got some buffer alerts but the output video was much better than mine, without artifacts.
When I'm encoding should I order the frames in some way? Cheers 2015-02-27 10:05 GMT+00:00 Eng. Tweellt <twee...@gmail.com>: > > 2015-02-26 23:46 GMT+00:00 Michael Niedermayer <michae...@gmx.at>: > >> On Thu, Feb 26, 2015 at 05:26:36PM +0000, Eng. Tweellt wrote: >> > Hello everyone, >> > >> > I'm trying to encode video and audio directly from a capture board, 1 >> video >> > stream and 8 single channel audio streams into a MXF file encoding it in >> > Mpeg-2. >> > >> > Everything is working fine except when I call av_write_trailer() at the >> end >> > (and before freeing CodecContext as stated in the documentation). >> > >> > After using av_write_trailer, I end up with the whole video looking like >> > this http://i.imgur.com/M6HkcpR.jpg . It seems like the decoder is >> > misplacing the b-frames in the wrong position, but If i don't call this >> > function I can play the media file, with the image as it should be, in >> VLC >> > but the timestamp is completely wrong. >> > Looking at mediainfo I can see that my file doesn't have the file >> duration >> > (which later made sense when I looked inside the code.) >> > >> > After a few hours with the file mxfenc.c found that if I comment the >> next >> > part inside the function mxf_write_footer(), the write trailer "kinda" >> > works, >> > >> > (...) >> > if (mxf->edit_unit_byte_count && s->oformat != &ff_mxf_opatom_muxer) { >> // >> > no need to repeat index >> > if ((err = mxf_write_partition(s, 0, 0, footer_partition_key, >> 0)) < >> > 0) >> > return err; >> > } /*else { >> > if ((err = mxf_write_partition(s, 0, 2, footer_partition_key, >> 0)) < >> > 0) >> > return err; >> > mxf_write_klv_fill(s); >> > mxf_write_index_table_segment(s); >> > }*/ >> > (...) >> > >> > The "kinda" works part, its because I can play the file correctly in VLC >> > with the correct timestamps, and if I open it with Mediainfo everything >> > looks good, but If I try to open it with Sorenson Squeeze (for >> example), I >> > get a warning saying "Squeeze does not support playing this file". >> > I carefully followed the documentation, samples, examples and I'm still >> > stuck :S. >> > I am using the ffmpeg 2.5.1 version and I also added a few changes that >> I >> > saw in the master, and nothing changed. >> > >> > Additional info: >> > >> > Target Output file format is a 1080i59.94, XDCam 30Mbit MXF op1a. >> > >> > Regarding the 8 audio streams the codec options have the one provided by >> > avcodec_get_context_defaults3 plus this changes: >> > >> > audio_codec_context->channels=1; >> > audio_codec_context->sample_rate = 48000; >> > audio_codec_context->bit_rate = 768000; >> > audio_codec_context->sample_fmt =AV_SAMPLE_FMT_S16; >> > audio_codec_context->flags= CODEC_FLAG_GLOBAL_HEADER; >> > audio_codec_context->time_base->num = 48000; >> > >> > >> > Regarding video I also do avcodec_get_context_defaults3 plus this: >> > >> > video_codec_context-> pix_fmt= AV_PIX_FMT_YUV422P; >> > video_codec_context->height = 1080; >> > video_codec_context->time_base->den = 30000; >> > video_codec_context->time_base->num = 1001; >> > video_codec_context->field_order= AVFieldOrder.AV_FIELD_TB; >> > video_codec_context->width = 1920; >> > video_codec_context->codec_id= AV_CODEC_ID_MPEG2VIDEO; >> > video_codec_context->has_b_frames= 1; >> > video_codec_context->max_b_frames = 2; >> > video_codec_context->gop_size= 12; >> > video_codec_context->global_quality= FF_QP2LAMBDA * 1; >> > video_codec_context->rc_initial_buffer_occupancy= 10695476; >> > video_codec_context->scenechange_threshold = 1000000000; >> > video_codec_context->color_primaries= AVCOL_PRI_BT709; >> > video_codec_context->color_trc= AVCOL_TRC_BT709; >> > video_codec_context->qmin= 1; >> > video_codec_context->flags |= CODEC_FLAG_GLOBAL_HEADER | >> > CODEC_FLAG_INTERLACED_DCT | CODEC_FLAG_INTERLACED_ME; >> > video_codec_context->bit_rate = 30000000; >> > video_codec_context->rc_min_rate= 30000000; >> > video_codec_context->rc_max_rate= 30000000; >> > video_codec_context->rc_buffer_size= 10695476; >> > >> > >> > I also had specified me_method and me_range, but nothing changed. >> > >> > Any idea what might be the problem? >> >> can the problem be reproduced with command line FFmpeg ? >> >> [...] >> -- >> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB >> >> While the State exists there can be no freedom; when there is freedom >> there >> will be no State. -- Vladimir Lenin >> > > > Hi Michael, > > I can't really tell. Encoding from another file seams to work fine but > encoding from a live source it does not. > > Now there are some differences, for instance when getting frames from a > live source I have to deal with PTS values, duration and so on. > > Is there a way to encode directly from a live source using command line? > > Cheers > > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
