[FFmpeg-devel] Live encoding into mxf...
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 = 3;
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 = 10;
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 = 3000;
video_codec_context->rc_min_rate= 3000;
video_codec_context->rc_max_rate= 3000;
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?
Thanks guys,
Cheers
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Re: [FFmpeg-devel] Live encoding into mxf...
2015-02-26 23:46 GMT+00:00 Michael Niedermayer :
> 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 = 3;
> > 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 = 10;
> > 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 = 3000;
> > video_codec_context->rc_min_rate= 3000;
> > video_codec_context->rc_max_rate= 3000;
> > 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
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Re: [FFmpeg-devel] Live encoding into mxf...
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 :
>
> 2015-02-26 23:46 GMT+00:00 Michael Niedermayer :
>
>> On Thu, Feb 26, 2015 at 05:26:36PM +, 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 = 3;
>> > 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 = 10;
>> > 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
