[FFmpeg-devel] [DEVEL][PATCH v2] ffmpeg: fix channel_layout bug on non-default layout
pkv.stream
pkv.stream at gmail.com
Sun Nov 12 18:17:38 EET 2017
Le 12/11/2017 à 5:00 PM, Michael Niedermayer a écrit :
> On Sat, Nov 11, 2017 at 02:15:25AM +0100, pkv.stream wrote:
>> Le 11/11/2017 à 1:07 AM, Michael Niedermayer a écrit :
>>> On Fri, Nov 10, 2017 at 10:27:48PM +0100, pkv.stream wrote:
>>>> Le 10/11/2017 à 1:12 AM, Michael Niedermayer a écrit :
>>>>> On Thu, Nov 09, 2017 at 09:37:33PM +0100, pkv.stream wrote:
>>>>>> Hi Michael,
>>>>>>
>>>>>>>> ffmpeg_opt.c | 11 ++++++++++-
>>>>>>>> 1 file changed, 10 insertions(+), 1 deletion(-)
>>>>>>>> 2af07f4366efdfaf1018bb2ea29be672befe0823 0001-ffmpeg-fix-channel_layout-bug-on-non-default-layout.patch
>>>>>>>> From 4ec55dc88923108132307b41300a1abddf32e6f7 Mon Sep 17 00:00:00 2001
>>>>>>>> From: pkviet <pkv.stream at gmail.com>
>>>>>>>> Date: Mon, 2 Oct 2017 11:14:31 +0200
>>>>>>>> Subject: [PATCH] ffmpeg: fix channel_layout bug on non-default layout
>>>>>>>>
>>>>>>>> Fix for ticket 6706.
>>>>>>>> The -channel_layout option was not working when the channel layout was not
>>>>>>>> a default one (ex: for 4 channels, quad was interpreted as 4.0 which is
>>>>>>>> the default layout for 4 channels; or octagonal interpreted as 7.1).
>>>>>>>> This led to the spurious auto-insertion of an auto-resampler filter
>>>>>>>> remapping the channels even if input and output had identical channel
>>>>>>>> layouts.
>>>>>>>> The fix operates by directly calling the channel layout if defined in
>>>>>>>> options. If the layout is undefined, the default layout is selected as
>>>>>>>> before the fix.
>>>>>>>> ---
>>>>>>>> ffmpeg_opt.c | 11 ++++++++++-
>>>>>>>> 1 file changed, 10 insertions(+), 1 deletion(-)
>>>>>>>>
>>>>>>>> diff --git a/ffmpeg_opt.c b/ffmpeg_opt.c
>>>>>>>> index 100fa76..cf5a63c 100644
>>>>>>>> --- a/ffmpeg_opt.c
>>>>>>>> +++ b/ffmpeg_opt.c
>>>>>>>> @@ -1804,6 +1804,12 @@ static OutputStream *new_audio_stream(OptionsContext *o, AVFormatContext *oc, in
>>>>>>>> MATCH_PER_STREAM_OPT(audio_channels, i, audio_enc->channels, oc, st);
>>>>>>>> + AVDictionaryEntry *output_layout = av_dict_get(o->g->codec_opts,
>>>>>>>> + "channel_layout",
>>>>>>>> + NULL, AV_DICT_MATCH_CASE);
>>>>>>> This doesnt look right
>>>>>>>
>>>>>>> not an issue of the patch as such but
>>>>>>> why is the channel_layout option per file and not per stream?
>>>>>> just my ignorance; do you mean this is not the right way to retrieve
>>>>>> the channel_layout option from an audio stream ?
>>>>> I think there is more buggy with how the channel_layout is handled
>>>>>
>>>>> try this:
>>>>> ./ffmpeg -i ~/videos/matrixbench_mpeg2.mpg -channel_layout 5 test.wav
>>>>> and this:
>>>>> ./ffmpeg -i ~/videos/matrixbench_mpeg2.mpg -channel_layout:a 5 test.wav
>>>>>
>>>>> while it may appear that the are both working this is deceiving.
>>>>> I think only the channel number gets actually used in the 2nd case
>>>>>
>>>>> Look at what your code with av_dict_get() reads.
>>>>> It does not obtain the 5 in the 2nd case
>>>> ok I fixed that by using the flag AV_DICT_IGNORE_SUFFIX ; now
>>>> -channel_layout:a works as expected.
>>>> I fixed also all the styling issues you spotted (mixed declarations,
>>>> {} for if etc).
>>>>
>>>> Still not understanding your initial comment though :
>>>> 'why is the channel_layout option per file and not per stream?'
>>>>
>>>> do you mean o->g->codec_opts is not where I should retrieve the
>>>> channel_layout ? if not where from ?
>>>>
>>>> Thanks
>>>>
>>>>> [...]
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> ffmpeg-devel mailing list
>>>>> ffmpeg-devel at ffmpeg.org
>>>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>>> ffmpeg_opt.c | 12 ++++++++++--
>>>> 1 file changed, 10 insertions(+), 2 deletions(-)
>>>> 849898d28e989ffa5cc598c6fe4d43847b636132 0001-ffmpeg-fix-channel_layout-bug-on-non-default-layout.patch
>>>> From 6d4f1c14135f9473b77e1c649d0e7bbaeba00a50 Mon Sep 17 00:00:00 2001
>>>> From: pkviet <pkv.stream at gmail.com>
>>>> Date: Mon, 2 Oct 2017 11:14:31 +0200
>>>> Subject: [PATCH] ffmpeg: fix channel_layout bug on non-default layout
>>>>
>>>> Fix for ticket 6706.
>>>> The -channel_layout option was not working when the channel layout was not
>>>> a default one (ex: for 4 channels, quad was interpreted as 4.0 which is
>>>> the default layout for 4 channels; or octagonal interpreted as 7.1).
>>>> This led to the spurious auto-insertion of an auto-resampler filter
>>>> remapping the channels even if input and output had identical channel
>>>> layouts.
>>>> The fix operates by directly calling the channel layout if defined in
>>>> options. If the layout is undefined, the default layout is selected as
>>>> before the fix.
>>>> ---
>>>> fftools/ffmpeg_opt.c | 12 ++++++++++--
>>>> 1 file changed, 10 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
>>>> index ca6f10d..cb25d7b 100644
>>>> --- a/fftools/ffmpeg_opt.c
>>>> +++ b/fftools/ffmpeg_opt.c
>>>> @@ -1785,6 +1785,7 @@ static OutputStream *new_audio_stream(OptionsContext *o, AVFormatContext *oc, in
>>>> AVStream *st;
>>>> OutputStream *ost;
>>>> AVCodecContext *audio_enc;
>>>> + AVDictionaryEntry *output_layout;
>>>> ost = new_output_stream(o, oc, AVMEDIA_TYPE_AUDIO, source_index);
>>>> st = ost->st;
>>>> @@ -1799,7 +1800,10 @@ static OutputStream *new_audio_stream(OptionsContext *o, AVFormatContext *oc, in
>>>> char *sample_fmt = NULL;
>>>> MATCH_PER_STREAM_OPT(audio_channels, i, audio_enc->channels, oc, st);
>>>> -
>>>> + output_layout = av_dict_get(o->g->codec_opts,"channel_layout", NULL, AV_DICT_IGNORE_SUFFIX);
>>> i didnt try but i assume
>>> this would fail if there are 2 audio streams each with different
>>> layout
>> ah ok, I understand now; thanks for elaborating.
>> i tested with two output streams, it's not failing and working correctly.
>>
>> ex: ffmpeg -channel_layout octagonal -i source.wav -c:a pcm_s16le
>> -channel_layout octagonal out1.wav -c:a pcm_s16le -channel_layout
>> quad out2.wav
>>
>> (if I pick layout 0x5 as in your examples it fails because the
>> rematrix is not supported, so this is expected behavior although
>> failing; but with pan filter it eventually works)
>>
>> Tested also with two source streams used for two ouputs. Working too.
> have you tried with different layouts for each stream ?
ps:
example:
ffmpeg -loglevel debug -channel_layout octagonal -i octagonal.wav
-channel_layout quad -i quad.wav \
-map 0:a -c:a pcm_s16le -channel_layout octagonal test1.wav -map 1:a
-channel_layout quad test2.wav
(sources are 24 bit pcm)
>
> [...]
>
>
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