1042725 - getUserMedia: Sample rate in Mozilla Firefox is low

Status: RESOLVED DUPLICATE of bug 953265

(Core :: WebRTC: Audio/Video, defect)

Description

[Rainer Rillke]

Attachment: Comparison of the waveform graphs of sound recorded by Firefox and Chrome -- note the "S" and "X"

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:30.0) Gecko/20100101 Firefox/30.0 (Beta/Release)
Build ID: 20140605174243

Steps to reproduce:

0. Plug-In a good microphone allowing sample rates of 44100 Hz.
1. Go to http://tools.wmflabs.org/rillke/prg/test.html using Firefox and Chrome. Do the same simultaneously for both browsers.
2. Press "Request Mic Access"
3. Press "Record"
4. Say something with a hard "s" in it.
5. Press "Stop recording"
6. Press "Append Player"
7. Listen to both samples (on Firefox and on Chrome).

This page is utilizing https://github.com/mattdiamond/Recorderjs -- you should be able reproducing the issue on other pages.


Actual results:

Mozilla Firefox samples the signal down, though still claiming recording with a sample rate of 48000Hz (context.sampleRate). Listening to a recording created with Chrome and compare them with Firefox, the difference is manifest. Chrome records with the quality I am used from using native recording tools.


Expected results:

Mozilla Firefox should allow recording with 44100 Hz.

Comment 1

[Rainer Rillke]

Attachment: Original sound produced by Firefox

Comment 2

[Rainer Rillke]

Attachment: Original sound produced by Chrome

Comment 3

[Randy Lin [:rlin] - Be Mozillian on 2015/01/26]

Change to WebAudio component because the test step don't invoke the MediaRecorder API.

Comment 4

[kevin]

I'm noticing this too. If I play a sound with a higher frequency, it does not show up in the resulting data.

Comment 5

[kevin]

Attachment: Recording of high frequency sound that doesn't not show in output

Comment 6

[Randell Jesup [:jesup] (needinfo me)]

First target is 32KHz right now; 44100/48000 ('natural' system frequency) preferred to minimize resamples.