[FFmpeg-devel] [PATCH 3/3] fate: add loudnorm filter test

Marton Balint cus at passwd.hu
Tue Oct 18 03:20:03 EEST 2016

On Tue, 18 Oct 2016, Michael Niedermayer wrote:

> On Sun, Oct 16, 2016 at 10:12:17PM +0200, Marton Balint wrote:
>> On Sun, 16 Oct 2016, Marton Balint wrote:
>>> Signed-off-by: Marton Balint <cus at passwd.hu>
>>> ---
>>> tests/fate/filter-audio.mak | 7 +++++++
>>> 1 file changed, 7 insertions(+)
>>> diff --git a/tests/fate/filter-audio.mak b/tests/fate/filter-audio.mak
>>> index 9c6f7cd..d376f25 100644
>>> --- a/tests/fate/filter-audio.mak
>>> +++ b/tests/fate/filter-audio.mak
>>> @@ -279,6 +279,13 @@ fate-filter-hdcd-detect-errors: CMD = md5 -i $(SRC) -af hdcd -f s24le
>>> fate-filter-hdcd-detect-errors: CMP = grep
>>> fate-filter-hdcd-detect-errors: REF = detectable errors: [1-9]
>>> +FATE_AFILTER-$(call FILTERDEMDECENCMUX, LOUDNORM, AAC, AAC, PCM_S16LE, PCM_S16LE) += fate-filter-loudnorm-simple
>>> +fate-filter-loudnorm-simple: SRC = $(SAMPLES)/aac/sintel.aac
>>> +fate-filter-loudnorm-simple: CMD = ffmpeg -t 30 -i $(SRC) -af loudnorm=i=-23 -f s16le -ar 44100 -
>>> +fate-filter-loudnorm-simple: REF = $(SAMPLES)/filter/loudnorm-simple.pcm
>>> +fate-filter-loudnorm-simple: CMP = oneoff
>>> +fate-filter-loudnorm-simple: CMP_UNIT = s16
>>> +
>> This patch needs two files in the fate samples:
>> The audio part of the Sintel movie, as a source, because I wanted to
>> test with a real world example, with proper length. And the
>> reference file. Sources can be generated like this:
>> wget http://media.xiph.org/sintel/sintel-master-st.flac
>> ffmpeg -i sintel-master-st.flac -codec aac -b 96k fate-suite/aac/sintel.aac
>> ffmpeg -t 30 -i fate-suite/aac/sintel.aac -af loudnorm=i=-23 -f s16le -ar 44100 fate-suite/filter/loudnorm-simple.pcm
>> Due to the 96k AAC codec, sintel.aac is about 15M,
> are low bitrate speech codecs unsuitable instead of aac for this ?
> that would cut the size down by alot

In theory, maybe, on the other hand, we are only using the first 30 second 
of the sample, so if size is an issue, we can reduce it to around 500k and 
the fate test will still work.

Since the reference file alone is 6M, it does not seem to make too much 
difference if the sample is 500k, or less, so I'd prefer the 
normal codec. I am not sure I can give you a pure technical reasoning, the 
only thing I could think of is that as far as I know a speech codec is 
usually not good at very low or very high frequencies, but it is a 
good idea to test loudness measurement with all kind of frequencies, 
because of it's frequency dependant filters.


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