[FFmpeg-user] concat video requirements

[Tony Lambropoulos]

Hey Gyan,
I've ensured the SAR ratios and resolutions match up.  The results are
still pretty funky, however.  The first video last far longer than it's
supposed to and the second video is running in slow motion.  Is there
nothing else that should match up?

Here are the specs on the two input videos (first and second respectively):

tony at ubuntu:/mnt/hgfs/vloop/transcoding$ ffmpeg -i /tmp/here2.mp4

ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers

  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3)

  configuration: --prefix=/home/tony/ffmpeg_build
--pkg-config-flags=--static
--extra-cflags=-I/home/tony/ffmpeg_build/include
--extra-ldflags=-L/home/tony/ffmpeg_build/lib --bindir=/home/tony/bin
--enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype
--enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis
--enable-libvpx --enable-libx264 --enable-nonfree

  libavutil      55. 34.101 / 55. 34.101

  libavcodec     57. 64.101 / 57. 64.101

  libavformat    57. 56.101 / 57. 56.101

  libavdevice    57.  1.100 / 57.  1.100

  libavfilter     6. 65.100 /  6. 65.100

  libswscale      4.  2.100 /  4.  2.100

  libswresample   2.  3.100 /  2.  3.100

  libpostproc    54.  1.100 / 54.  1.100

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/here2.mp4':

  Metadata:

    major_brand     : isom

    minor_version   : 512

    compatible_brands: isomiso2avc1mp41

    encoder         : Lavf57.56.101

  Duration: 00:00:05.00, start: 0.000000, bitrate: 104 kb/s

    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
720x260 [SAR 1:1 DAR 36:13], 93 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc
(default)

    Metadata:

      handler_name    : VideoHandler

    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz,
stereo, fltp, 2 kb/s (default)

    Metadata:

      handler_name    : SoundHandler

At least one output file must be specified

tony at ubuntu:/mnt/hgfs/vloop/transcoding$ ffmpeg -i
/tmp/6d41bcedfe4849cf5a9a244ce159d0bd.mp4

ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers

  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3)

  configuration: --prefix=/home/tony/ffmpeg_build
--pkg-config-flags=--static
--extra-cflags=-I/home/tony/ffmpeg_build/include
--extra-ldflags=-L/home/tony/ffmpeg_build/lib --bindir=/home/tony/bin
--enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype
--enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis
--enable-libvpx --enable-libx264 --enable-nonfree

  libavutil      55. 34.101 / 55. 34.101

  libavcodec     57. 64.101 / 57. 64.101

  libavformat    57. 56.101 / 57. 56.101

  libavdevice    57.  1.100 / 57.  1.100

  libavfilter     6. 65.100 /  6. 65.100

  libswscale      4.  2.100 /  4.  2.100

  libswresample   2.  3.100 /  2.  3.100

  libpostproc    54.  1.100 / 54.  1.100

Input #0, mpegts, from '/tmp/6d41bcedfe4849cf5a9a244ce159d0bd.mp4':

  Duration: 00:00:09.02, start: 1.456711, bitrate: 1003 kb/s

  Program 1

    Metadata:

      service_name    : Service01

      service_provider: FFmpeg

    Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B),
yuv420p(progressive), 720x260 [SAR 1:1 DAR 36:13], 29.97 fps, 29.97 tbr,
90k tbn, 59.94 tbc

    Stream #0:1[0x101]: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz,
stereo, s16p, 384 kb/s


Thanks,

Tony

On Mon, Jul 17, 2017 at 2:20 PM, Gyan <gyandoshi at gmail.com> wrote:

> On Tue, Jul 18, 2017 at 12:37 AM, Tony Lambropoulos <tonyl7126 at gmail.com>
> wrote:
>
> >
> > Does anyone have a specific list of these attributes to ensure the concat
> > command is successful?
> >
>
> For video streams, resolution and SAR have to match. Pixel format and frame
> rate need not match. Since the filter operates upon decoded frames, inputs'
> bitstream syntax i.e. codec is not relevant.
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