[Android] [PATCH] jni/aout: limit sample rate to 48kHz

[Rafaël Carré]

Le 19/10/2013 13:39, Zhang Rui a écrit :
>> Here is a 2kHz: http://people.videolan.org/~funman/bouteille.wav
> Thanks. And here is a 96khz: http://bili-test.u.qiniudn.com/aac-96khz.flv
> 
> Here is my test result with VLC android 0.1.3
> 
> Nexus 10 (4.3):
> amem: does not work
> audiotrack: Could not initialize libmedia.so!
> sles: does not work
> 
> Nexus S (4.1.2):
> amem: does not work
> audiotrack: does not work
> sles: does not work
> 
> Log of Nexus 10
> ==  using amem ==
> 10-19 19:07:10.525: D/VLC(25650): main generic: creating audio output
> 10-19 19:07:10.525: D/VLC(25650): main audio output: looking for audio
> output module matching "amem,none": 4 candidates
> 10-19 19:07:10.525: D/VLC(25650): main audio output: using audio
> output module "amem"
> 10-19 19:07:10.530: E/VLC(25650): main audio output: too low audio
> sample frequency (2000)

Ah I didn't know VLC hardcodes a lower limit at 4kHz, and an upper limit
at 352.8kHz

> 10-19 19:07:10.530: D/VLC(25650): main generic: keeping audio output
> 10-19 19:07:10.530: E/VLC(25650): main decoder: failed to create audio output
> 
> ==  using audiotrack, sles ==
> 10-19 19:10:28.015: D/VLC(25650): main audio output: looking for audio
> output module matching "android_audiotrack": 4 candidates
> 10-19 19:10:28.015: E/VLC(25650): android_audiotrack audio output:
> Could not initialize libmedia.so!
> 10-19 19:10:28.015: D/VLC(25650): main audio output: using audio
> output module "opensles_android"
> 10-19 19:10:28.015: E/VLC(25650): main audio output: too low audio
> sample frequency (2000)
> 10-19 19:10:28.015: D/VLC(25650): main generic: keeping audio output
> 10-19 19:10:28.015: E/VLC(25650): main decoder: failed to create audio output
> 
> ==================
> ==================
> http://bili-test.u.qiniudn.com/aac-96khz.flv
> 96khz test
> 
> Nexus 10 (4.3):
> amem: does not work
> audiotrack: Could not initialize libmedia.so!
> sles: works after resample to 44.1khz

Right, OpenSLES module resamples to 44.1 if original rate fails.

Perhaps we could do the same in java aout? That method would be nicer
for all devices, no need to resample if some device accepts the original
rate.

> Nexus S (4.1.2):
> amem: does not work
> audiotrack: works after resample to 48khz
> sles: works after resample to 44.1khz
> 
> Log of Nexus 10
> ==  using amem ==
> 10-19 19:15:38.795: I/VLC/JNI/aout(25650): Opening the JNI audio output
> 10-19 19:15:38.795: I/VLC/JNI/aout(25650): Parameters: 2 channels,
> FOURCC 'S16N',  sample rate: 96000Hz
> 10-19 19:15:38.795: D/VLC/LibVLC(25650): Opening the java audio output
> 10-19 19:15:38.795: D/LibVLC/aout(25650): 96000, 2, 8192=>16384
> 10-19 19:15:38.795: E/VLC/JNI/aout(25650): Unable to create audio player!
> 
> ==  using audiotrack + sles == (only sles works)
> 10-19 19:13:48.600: D/VLC(25650): main audio output: looking for audio
> output module matching "android_audiotrack": 4 candidates
> 10-19 19:13:48.600: E/VLC(25650): android_audiotrack audio output:
> Could not initialize libmedia.so!
> 10-19 19:13:48.600: D/VLC(25650): main audio output: using audio
> output module "opensles_android"
> 10-19 19:13:48.605: D/VLC(25650): main audio output: output 's16l'
> 44100 Hz Stereo frame=1 samples/4 bytes
> 10-19 19:13:48.605: D/VLC(25650): main volume: looking for audio
> volume module matching "any": 3 candidates
> 10-19 19:13:48.605: D/VLC(25650): main volume: using audio volume
> module "integer_mixer"
> 10-19 19:13:48.605: D/VLC(25650): main audio output: input 'f32l'
> 96000 Hz Stereo frame=1 samples/8 bytes
> 10-19 19:13:48.610: D/VLC(25650): main audio output: conversion:
> 'f32l'->'s16l' 96000 Hz->96000 Hz Stereo->Stereo
> 10-19 19:13:48.610: D/VLC(25650): main audio converter: looking for
> audio converter module matching "any": 7 candidates
> 10-19 19:13:48.610: D/VLC(25650): audio_format audio converter:
> f32l->s16l, bits per sample: 32->16
> 10-19 19:13:48.610: D/VLC(25650): main audio converter: using audio
> converter module "audio_format"
> 10-19 19:13:48.610: D/VLC(25650): main audio output: conversion
> pipeline complete
> 10-19 19:13:48.610: D/VLC(25650): main audio resampler: looking for
> audio resampler module matching "any": 1 candidates
> 10-19 19:13:48.610: D/VLC(25650): main audio resampler: using audio
> resampler module "ugly_resampler"
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