Last Comment Bug 639587 - nsAudioStream U8 sound format conversion incorrect
: nsAudioStream U8 sound format conversion incorrect
Product: Core
Classification: Components
Component: Audio/Video (show other bugs)
: Trunk
: All All
-- normal (vote)
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Assigned To: Nobody; OK to take it and work on it
: Maire Reavy [:mreavy] Please needinfo me
Depends on: 775319
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Reported: 2011-03-07 12:52 PST by cajbir (:cajbir)
Modified: 2012-08-22 22:37 PDT (History)
1 user (show)
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Description User image cajbir (:cajbir) 2011-03-07 12:52:18 PST
Found while working on bug 635649. The code to covert from U8 sound samples to S16 format is incorrect. Existing code is:

s_data[i + offset] = short(((PRInt32(buf[i]) - 128) * volume) >> 8);

For a U8 value of 255 this gives a result of 32512. It should give 32767.

Matthew Gregan suggested fixing it as part of the audio backend refactoring.
Comment 1 User image Matthew Gregan [:kinetik] 2012-08-22 22:37:34 PDT
FORMAT_U8 conversion was removed from nsAudioStream in bug 775319.

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