[issue2255] ffmpeg h264 wss

[Janos Barta]

Janos Barta  added the comment:

Sorry but I made a typo :(.
I wanted to write 4:3,16:9 insted of SD,HD.
Sorry again.


FFmpeg issue tracker 

[issue2255] ffmpeg h264 wss

[Janos Barta]

Janos Barta  added the comment:

Hello,

thanks for your answer, but I do not agree with you.
I think it would be a very important feature.

If you are a broadcaster, then you may have a couple of channels.  One of these
channels is SD, others HD, and the rest are mixed resolutions. The mixed means,
sometimes the channel provides SD, other times HD resolution. In the last case
the PAR/DAR information is in a different elementary stream (if you have 
mpeg2ts). 
If you receive  it with a standard SetTopBox/mplayer/vlc, these devices can
display the stream with the correct aspect ratio, because they can read the
aspect information from the ES.

But if you want to display this stream with a special device, which does not
read the  VBI WSS ES, or you would like to transcode it (for example: you want
to make an iPhone stream), then you (the ffmpeg) need to handle the changes of
the resolution (eg. using the pillarbox, letterbox format).

We discussed about that on the doom forum, and I got an answer:
the libx264 does it, but there's no code that connects that support to
information provided by FFmpeg decoders.


What can I do now? Should I modify the status of the report (to feature
request), or should I close it?

Thanks,
Jani


FFmpeg issue tracker 

[issue2255] ffmpeg h264 wss

[Carl Eugen Hoyos]

Carl Eugen Hoyos  added the comment:

FFmpeg currently does not warn that it does not support aspect ratio changes
with libx264.

--
substatus: needs_more_info -> open


FFmpeg issue tracker 

[issue2255] ffmpeg h264 wss

[Kieran K]

Kieran K  added the comment:

As discussed on doom10 (http://doom10.org/index.php?topic=653.0) patch 
welcome to pass through AFDs to libx264.


FFmpeg issue tracker 

[issue2255] ffmpeg h264 wss

[Carl Eugen Hoyos]

Carl Eugen Hoyos  added the comment:

Apart from the fact that this is completely unrelated to your sample and
widescreen signalling: Does x264 support aspect ratio changes?

--
status: new -> open
substatus: new -> needs_more_info


FFmpeg issue tracker 

[issue2255] ffmpeg h264 wss

[Janos Barta]

New submission from Janos Barta :

Hello,

I have a special mpeg2ts transport stream, that contains WSS (widescreen
signaling) information.
The ffmpeg can open that transport stream -and always opens it with the right
aspect ratio-, but can not handle the changes of the screen -during the
transcoding- dynamicly (16:9 <-> 4:3), when I use libx264 codec.

The ffmpeg works (the aspect change) fine, when I use mpeg2video:

ffmpeg -i wss_change.ts -an ./test.ts
FFmpeg version git-0097d3b, Copyright (c) 2000-2010 the FFmpeg 
developers
  built on Sep 20 2010 15:34:00 with gcc 4.3.2

  configuration: --enable-avfilter --prefix=/usr/ --enable-gpl
--enable-nonfree --enable-postproc --enable-avfilter --enable-pthreads
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libdirac
--enable-libfaac --enable-libmp3lame --enable-libvorbis --enable-libx264
--enable-libxvid --enable-version3 --enable-shared --enable-libdc1394
--enable-libopenjpeg --enable-libschroedinger --enable-libspeex --enable-libgsm
--enable-librtmp --enable-libnut --enable-libtheora --enable-libvpx
  libavutil 50.26. 0 / 50.26. 0
  libavcore  0. 9. 0 /  0. 9. 0
  libavcodec52.89. 0 / 52.89. 0
  libavformat   52.78. 4 / 52.78. 4
  libavdevice   52. 2. 2 / 52. 2. 2
  libavfilter1.38. 3 /  1.38. 3

  libswscale 0.11. 0 /  0.11. 0
  libpostproc   51. 2. 0 / 51. 2. 0
   
Seems stream 0 codec frame rate differs from container frame rate: 50.00
(50/1) -> 450.00 (450/1)
Input #0, mpegts, from 'wss_change.ts':
  Duration: 00:00:04.48, start: 3.00, bitrate: 2628 kb/s
  Program 1
Stream #0.0[0x800]: Video: h264, yuv420p, 704x576 [PAR 16:11 DAR
16:9], 25.45 fps, 450 tbr, 90k tbn, 50 tbc
Stream #0.1[0x1f68](hun): Subtitle: [6][0][0][0] / 0x0006
Stream #0.2[0x1f69]: Data: [6][0][0][0] / 0x0006
Stream #0.3[0x1f43](hun): Audio: mp2, 48000 Hz, 2 channels, s16, 128
kb/s
Stream #0.4[0x1f46](eng): Audio: mp2, 48000 Hz, 2 channels, s16, 128
kb/s
File './test.ts' already exists. Overwrite ? [y/N] y
[buffer @ 0x143ef00] w:704 h:576 pixfmt:yuv420p
[mpegts @ 0x1441f20] muxrate VBR, pcr every 6 pkts, sdt every 200,
pat/pmt every 40 pkts
Output #0, mpegts, to './test.ts':
  Metadata:
encoder : Lavf52.78.4
Stream #0.0: Video: mpeg2video, yuv420p, 704x576 [PAR 16:11 DAR
16:9], q=2-31, 200 kb/s, 90k tbn, 60 tbc
Stream mapping:
  Stream #0.0 -> #0.0
Press [q] to stop encoding
frame= 3986 fps=558 q=31.0 Lsize=5985kB time=66.42 bitrate=
738.2kbits/s dup=3875 drop=1   
video:5284kB audio:0kB global headers:0kB muxing overhead 13.266869%
   

It works fine too, when I use mpeg4:

ffmpeg -i wss_change.ts -an ./test.avi
FFmpeg version git-0097d3b, Copyright (c) 2000-2010 the FFmpeg 
developers
  built on Sep 20 2010 15:34:00 with gcc 4.3.2

  configuration: --enable-avfilter --prefix=/usr/ --enable-gpl
--enable-nonfree --enable-postproc --enable-avfilter --enable-pthreads
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libdirac
--enable-libfaac --enable-libmp3lame --enable-libvorbis --enable-libx264
--enable-libxvid --enable-version3 --enable-shared --enable-libdc1394
--enable-libopenjpeg --enable-libschroedinger --enable-libspeex --enable-libgsm
--enable-librtmp --enable-libnut --enable-libtheora --enable-libvpx
  libavutil 50.26. 0 / 50.26. 0
  libavcore  0. 9. 0 /  0. 9. 0
  libavcodec52.89. 0 / 52.89. 0
  libavformat   52.78. 4 / 52.78. 4
  libavdevice   52. 2. 2 / 52. 2. 2
  libavfilter1.38. 3 /  1.38. 3

  libswscale 0.11. 0 /  0.11. 0
  libpostproc   51. 2. 0 / 51. 2. 0
   
Seems stream 0 codec frame rate differs from container frame rate: 50.00
(50/1) -> 450.00 (450/1)
Input #0, mpegts, from 'wss_change.ts':
  Duration: 00:00:04.48, start: 3.00, bitrate: 2628 kb/s
  Program 1
Stream #0.0[0x800]: Video: h264, yuv420p, 704x576 [PAR 16:11 DAR
16:9], 25.45 fps, 450 tbr, 90k tbn, 50 tbc
Stream #0.1[0x1f68](hun): Subtitle: [6][0][0][0] / 0x0006
Stream #0.2[0x1f69]: Data: [6][0][0][0] / 0x0006
Stream #0.3[0x1f43](hun): Audio: mp2, 48000 Hz, 2 channels, s16, 128
kb/s
Stream #0.4[0x1f46](eng): Audio: mp2, 48000 Hz, 2 channels, s16, 128
kb/s
File './test.avi' already exists. Overwrite ? [y/N] y
[buffer @ 0x1e8df30] w:704 h:576 pixfmt:yuv420p
Output #0, avi, to './test.avi':
  Metadata:
ISFT: Lavf52.78.4
Stream #0.0: Video: mpeg4, yuv420p, 704x576 [PAR 16:11 DAR 16:9],
q=2-31, 200 kb/s, 450 tbn, 450 tbc
Stream mapping:
  Stream #0.0 -> #0.0
Press [