[FFmpeg-user] capture mpeg2 from dvdlast

Fri Nov 23 19:50:59 EET 2018

On Fri, Nov 23, 2018 at 1:02 PM Javier Fuentes <jfuentes at flumotion.com>
wrote:

> Hello everybody
>
> Sorry for my delay in reply in my response.
> 1)I have attached a link for a small section of the flow that I capture
>
> https://drive.google.com/file/d/1c7IwXuu9GLMDo70A8gRyy1pUKntgxrM0/view?usp=sharing
>
> 2) I catpure multiple dvb-t or dvb-s signal with dvblast and his outgoing
> are rtp, then I use the rpt to transcoding the signal with ffmpeg mp2g to
> h264 and audio to aac. and republish it to my server.
>
> Thanks a lot for your help.
> Best regards
>
> On Fri, Nov 23, 2018 at 3:43 PM Javier Fuentes <jfuentes at flumotion.com>
> wrote:
>
> > Hello everybody
> >
> > Sorry for my delay in reply in my response.
> > 1)I have attached a small section of the flow that I capture
> > 2) I catpure multiple dvb-t or dvb-s signal with dvblast and his outgoing
> > are rtp, then I use the rpt to transcoding the signal with ffmpeg mp2g to
> > h264 and audio to aac. and republish it to my server.
> >
> > Thanks a lot for your help.
> > Best regards
> >
> > On Thu, Nov 22, 2018 at 5:49 PM Carl Eugen Hoyos <ceffmpeg at gmail.com>
> > wrote:
> >
> >> 2018-11-22 17:36 GMT+01:00, Javier Fuentes <jfuentes at flumotion.com>:
> >> > Hello Everybody
> >> >
> >> >
> >> > I have this ffmpeg command
> >> > ffmpeg -i rtp://127.0.0.1:6000 -map 0:4 -map 0:2 -vcodec libx264 -b:v
> >> 1500k
> >> > -s 720x576 -acodec aac  -ab 128k -ac 2 -ar 48000 -r 25 -f flv
> >> > rtmp://encoder....
> >> >
> >> > I have a lot of errors when i start capture a mpeg2 signal, and after
> a
> >> > while the capture starts to fail
> >> >
> >> > Thanks a lot for your help
> >> > Best regards
> >> >
> >> > My log
> >> > ffmpeg version git-2018-11-12-ae43235 Copyright (c) 2000-2018 the
> FFmpeg
> >> > developers
> >> >   built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-28)
> >> >   configuration: --prefix=/root/ffmpeg_build
> >> > --extra-cflags=-I/root/ffmpeg_build/include
> >> > --extra-ldflags=-L/root/ffmpeg_build/lib --bindir=/root/bin
> >> > --extra-libs=-ldl --enable-gpl --enable-nonfree --enable-libfdk_aac
> >> > --enable-libmp3lame --enable-libvpx --enable-libx264
> >> --enable-libfreetype
> >>
> >> > --enable-libspeex --enable-libtheora --enable-libass --enable-avfilter
> >> > --enable-pthreads --enable-decoder=mpeg4 --enable-decoder=mpegvideo
> >> > --enable-parser=mpeg4video --enable-parser=mpegvideo
> >> > --enable-muxer=mpeg2video --enable-muxer=mp4 --enable-muxer=h264
> >> > --enable-demuxer=h264 --enable-parser=ac3 --enable-parser=h261
> >> > --enable-parser=vc1 --enable-decoder=aac --enable-parser=aac
> >> > --enable-demuxer=aac --enable-demuxer=vc1 --enable-decoder=h264
> >> > --enable-parser=h264 --enable-demuxer=h264 --enable-muxer=h264
> >>
> >> While this is probably unrelated, these unused options make
> >> the issue needlessly harder to debug...
> >>
> >> >   libavutil      56. 23.101 / 56. 23.101
> >> >   libavcodec     58. 39.100 / 58. 39.100
> >> >   libavformat    58. 22.100 / 58. 22.100
> >> >   libavdevice    58.  6.100 / 58.  6.100
> >> >   libavfilter     7. 43.100 /  7. 43.100
> >> >   libswscale      5.  4.100 /  5.  4.100
> >> >   libswresample   3.  4.100 /  3.  4.100
> >> >   libpostproc    55.  4.100 / 55.  4.100
> >> > [mpeg2video @ 0x2befc40] Invalid frame dimensions 0x0.
> >> >     Last message repeated 13 times
> >> > Input #0, rtp, from 'rtp://127.0.0.1:6000':
> >> >   Duration: N/A, start: 51639.509822, bitrate: N/A
> >> >   Program 493
> >> >     Metadata:
> >> >       service_name    : Clan
> >> >       service_provider: RTVE
> >> >     Stream #0:4: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002),
> >> > yuv420p(tv, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr,
> >> 90k
> >> > tbn, 50 tbc
> >> >     Stream #0:0(spa,spa,qaa): Subtitle: dvb_teletext ([6][0][0][0] /
> >> 0x0006)
> >> >     Stream #0:1(spa): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz,
> >> stereo,
> >> > s16p, 128 kb/s
> >> >     Stream #0:3(qaa): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz,
> >> stereo,
> >> > s16p, 128 kb/s
> >> >     Stream #0:2(spa): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz,
> >> mono,
> >> > s16p, 96 kb/s (visual impaired) (descriptions)
> >> >     Stream #0:5(spa): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
> >> >     Stream #0:6(qaa): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
> >> > Stream mapping:
> >> >   Stream #0:4 -> #0:0 (mpeg2video (native) -> h264 (libx264))
> >> >   Stream #0:2 -> #0:1 (mp2 (native) -> aac (native))
> >> > Press [q] to stop, [?] for help
> >> > [libx264 @ 0x2c50340] using SAR=64/45
> >> > [libx264 @ 0x2c50340] using cpu capabilities: none!
> >> > [libx264 @ 0x2c50340] profile High, level 3.0, 4:2:0, 8-bit
> >> > [libx264 @ 0x2c50340] 264 - core 157 - H.264/MPEG-4 AVC codec -
> Copyleft
> >> > 2003-2018 - http://www.videolan.org/x264.html - options: cabac=1
> ref=3
> >> > deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00
> >> > mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0
> >> deadzone=21,11
> >> > fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2
> >> > sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0
> >> > constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1
> >> > weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40
> >> > intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=1500
> ratetol=1.0
> >> > qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
> >> > Output #0, flv, to 'rtmp://
> >> encoder-cg10.bt.bcn.flumotion.net:1935/yuvod/clan
> >> > ':
> >> >   Metadata:
> >> >     encoder         : Lavf58.22.100
> >> >     Stream #0:0: Video: h264 (libx264) ([7][0][0][0] / 0x0007),
> yuv420p,
> >> > 720x576 [SAR 64:45 DAR 16:9], q=-1--1, 1500 kb/s, 25 fps, 1k tbn, 25
> tbc
> >> >     Metadata:
> >> >       encoder         : Lavc58.39.100 libx264
> >> >     Side data:
> >> >       cpb: bitrate max/min/avg: 0/0/1500000 buffer size: 0 vbv_delay:
> -1
> >> >     Stream #0:1(spa): Audio: aac (LC) ([10][0][0][0] / 0x000A), 48000
> >> Hz,
> >> > stereo, fltp, 128 kb/s (visual impaired) (descriptions)
> >> >     Metadata:
> >> >       encoder         : Lavc58.39.100 aac
> >> > [rtp @ 0x2b9ab40] max delay reached. need to consume packet
> >> > bitrate=1458.5kbits/s speed=1.02x
> >> > [rtp @ 0x2b9ab40] RTP: missed 13 packets
> >>
> >> Can you try to record the network stream to allow us to reproduce?
> >> Why is rtp input from the local system necessary?
> >>
> >> Carl Eugen
> >> _______________________________________________
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> >> ffmpeg-user at ffmpeg.org
> >> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> >>
> >> To unsubscribe, visit link above, or email
> >> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
> >
> >
> >
> > --
> >
> >
> > Javier Fuentes
> > Flumotion Services S.A.
> >
> > Avda. Diagonal 579-587 7º
> > 08021 Barcelona - Spainwww.flumotion.com
>

I see you don't quite understand what I asked (capture the stream, but not
convert it to h264 on that pass) but from the file is possible to tell that
the problem probably is what I think it is. It starts well because ffmpeg
makes some buffer to analyze the media type on start but when it runs out
the frame dropping starts. The fact that the original codec there is MPEG2
delays that dropping some time, here we use H264 for transmission and it
makes the same scenario a little bit fast and worst.

I'm building a test scenario here for some tests and I'll report the
findings.