Commit FS#10422 by Yoshihisa Uchida. Seperates WAV and AIFF parsing from PCM decoding by introducing libpcm, a library for decoding linear and non-uniform PCM independently of the container format.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24346 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 120 insertions, 0 deletions

diff --git a/apps/codecs/libpcm/pcm_common.h b/apps/codecs/libpcm/pcm_common.h
new file mode 100644
index 0000000..757d0ad
--- /dev/null
+++ b/apps/codecs/libpcm/pcm_common.h
@@ -0,0 +1,120 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2009 Yoshihisa Uchida
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef CODEC_LIBPCMS_PCM_COMMON_H
+#define CODEC_LIBPCMS_PCM_COMMON_H
+
+#include <sys/types.h>
+#include <stdbool.h>
+#include <inttypes.h>
+
+/*
+ * PCM_CHUNK_SIZE has the size only of storing the sample at 1/50 seconds.
+ * But it might not be 1/50 seconds according to the format.
+ * Please confirm the source file of each format.
+ */
+#define PCM_CHUNK_SIZE (4096*2)
+
+/* Macro that sign extends an unsigned byte */
+#define SE(x) ((int32_t)((int8_t)(x)))
+
+/* Macro that shift to -0x80. (0 .. 127 to -128 .. -1, 128 .. 255 to 0 .. 127) */
+#define SFT(x) ((int32_t)x-0x80)
+
+struct pcm_format {
+    /*
+     * RIFF: wFormatTag (in 'fmt ' chunk)
+     * AIFF: compressionType (in 'COMM' chunk)
+     */
+    uint32_t formattag;
+
+    /*
+     * RIFF: wChannels (in 'fmt ' chunk)
+     * AIFF: numChannels (in 'COMM' chunk)
+     */
+    uint16_t channels;
+
+    /*
+     * RIFF: dwSamplesPerSec (in 'fmt ' chunk)
+     * AIFF: sampleRate (in 'COMM' chunk)
+     */
+    uint32_t samplespersec;
+
+    /* RIFF: dwAvgBytesPerSec (in 'fmt ' chunk) */
+    uint32_t avgbytespersec;
+
+    /*
+     * RIFF: wBlockAlign (in 'fmt ' chunk)
+     * AIFF: blockSize (in 'SSND' chunk)
+     */
+    uint16_t blockalign;
+
+    /*
+     * RIFF: wBitsPerSample (in 'fmt ' chunk)
+     * AIFF: sampleSize (in 'COMM' chunk)
+     */
+    uint16_t bitspersample;
+
+    /* RIFF: wSize (in 'fmt ' chunk) */
+    uint16_t size;
+
+    /* RIFF: dSamplesPerBlock (in 'fmt ' chunk) */
+    uint16_t samplesperblock;
+
+    /* RIFF: wTotalSamples (in 'fact' chunk) */
+    uint16_t totalsamples;
+
+    /* the following values are not RIFF/AIFF chunk values */
+
+    /* bytes per sample */
+    int bytespersample;
+
+    /* chunk size */
+    long chunksize;
+
+    /* data size */
+    uint32_t numbytes;
+
+    /*
+     * data endian
+     * true: little endian, false: big endian
+     */
+    bool is_little_endian;
+
+    /*
+     * data signess
+     * true: signed, false: unsigned
+     */
+    bool is_signed;
+};
+
+struct pcm_codec {
+    bool (*set_format)(struct pcm_format *format, const unsigned char *fmtpos);
+    uint32_t (*get_seek_pos)(long seek_time);
+    int (*decode)(const uint8_t *inbuf, size_t inbufsize,
+                  int32_t *outbuf, int *outbufsize);
+};
+
+struct pcm_entry {
+    uint32_t format_tag;
+    const struct pcm_codec *(*get_codec)(void);
+};
+
+#endif