[Gnash-commit] [patch #8736] Hack to workaround PCM embeded sound incremental decoding problem

[Nutchanon Wetchasit]

URL:
  <http://savannah.gnu.org/patch/?8736>

                 Summary: Hack to workaround PCM embeded sound incremental
decoding problem
                 Project: Gnash - The GNU Flash player
            Submitted by: nachanon
            Submitted on: Wed 09 Sep 2015 08:24:36 PM ICT
                Category: sound
                Priority: 5 - Normal
                  Status: None
                 Privacy: Public
             Assigned to: None
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any

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Details:

Current embeded _PCM_ sound decoder (both FFmpeg and GStreamer backend)
have some problem regarding incremental decoding
<https://savannah.gnu.org/bugs/?45722#comment12>. The problem surfaced
when the decoding block size is not a multiple of PCM frame size; resulting
in sample misalignment, producing screech sound (bug #45722).

This patch _works around_ the problem by requesting the decoder to decode
sound
in a block size of 65536 bytes, which is multiple of both 2-byte (16-bit
mono)
and 4-byte (16-bit stereo) PCM frame. (The original block size was 65535
<http://git.savannah.gnu.org/cgit/gnash.git/tree/libsound/EmbedSoundInst.cpp?id=c969f9d9d9ac40bfcb8e7c19b0f8ff5345f57c2d#n99>,
which was not a multiple of frame size in 16-bit PCM encoding).

See the attached `0001_use-frame-aligned-pcm-sound-decoding-chunk.patch`.

Gnash: 0.8.11dev (patched against git c969f9d 8-Sep-2015)
SDL: libsdl1.2debian 1.2.15-5 (debian)
libAV: libavcodec53 6:0.8.17-1 (debian), libavformat53 6:0.8.17-1 (debian),
libavutil51 6:0.8.17-1 (debian), libav-tools 6:0.8.10-1 (debian)
GStreamer: libgstreamer0.10-0 0.10.36-1.2 (debian)
CSound: libcsound64-5.2 1:5.17.11~dfsg-3 (debian)
System: Debian GNU/Linux 7.0 Wheezy i386



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File Attachments:


-------------------------------------------------------
Date: Wed 09 Sep 2015 08:24:36 PM ICT  Name:
0001_use-frame-aligned-pcm-sound-decoding-chunk.patch  Size: 787B   By:
nachanon
Patch to make Gnash embeded sound handler read audio in frame-aligned 64 KiB
chunk
<http://savannah.gnu.org/patch/download.php?file_id=34841>

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