[FFmpeg-trac] #4085(swresample:new): Support PLII upmixing
FFmpeg
trac at avcodec.org
Thu Nov 6 00:21:59 CET 2014
#4085: Support PLII upmixing
-------------------------------------+-------------------------------------
Reporter: cehoyos | Owner:
Type: | Status: new
enhancement | Component: swresample
Priority: wish | Keywords:
Version: git- | Blocking:
master | Analyzed by developer: 0
Blocked By: |
Reproduced by developer: 0 |
-------------------------------------+-------------------------------------
http://thread.gmane.org/gmane.comp.video.ffmpeg.user/54545
FFmpeg does support PLII down-mixing (see tickets #709 and #3455) but does
not support upmixing afaict. I will attach a sample from the MythTV
collection that plays surround sound on my receiver, upmixing to six
channels does not produce a similar result.
{{{
$ ffmpeg -i channelsPLII.mpg -ac 6 out.wav
ffmpeg version N-67396-g90cdec5 Copyright (c) 2000-2014 the FFmpeg
developers
built on Nov 6 2014 00:16:59 with gcc 4.7 (SUSE Linux)
configuration: --enable-gpl
libavutil 54. 11.100 / 54. 11.100
libavcodec 56. 10.102 / 56. 10.102
libavformat 56. 12.101 / 56. 12.101
libavdevice 56. 2.100 / 56. 2.100
libavfilter 5. 2.103 / 5. 2.103
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
Input #0, mpeg, from 'channelsPLII.mpg':
Duration: 00:00:31.82, start: 0.740000, bitrate: 462 kb/s
Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p(tv), 480x576
[SAR 8:5 DAR 4:3], max. 2420 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0:1[0x1c0]: Audio: mp2, 48000 Hz, stereo, s16p, 224 kb/s
Output #0, wav, to 'out.wav':
Metadata:
ISFT : Lavf56.12.101
Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, 5.1,
s16, 4608 kb/s
Metadata:
encoder : Lavc56.10.102 pcm_s16le
Stream mapping:
Stream #0:1 -> #0:0 (mp2 (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
size= 17915kB time=00:00:31.84 bitrate=4608.0kbits/s
video:0kB audio:17914kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: 0.000556%
}}}
MythTV contains a PLII decoder that supports upmixing under GPL.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/4085>
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