rockbox/apps/codecs/ape.c
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

335 lines
10 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 Dave Chapman
*
* 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.
*
****************************************************************************/
#include "codeclib.h"
#define ROCKBOX
#include <codecs/demac/libdemac/demac.h>
CODEC_HEADER
#define BLOCKS_PER_LOOP 4608
#define MAX_CHANNELS 2
#define MAX_BYTESPERSAMPLE 3
/* Monkey's Audio files have one seekpoint per frame. The framesize
varies between 73728 and 1179648 samples.
At the smallest framesize, 30000 frames would be 50155 seconds of
audio - almost 14 hours. This should be enough for any file a user
would want to play in Rockbox, given the 2GB FAT filesize (and 4GB
seektable entry size) limit.
This means the seektable is 120000 bytes, but we have a lot of
spare room in the codec buffer - the APE codec itself is small.
*/
#define MAX_SEEKPOINTS 30000
static uint32_t seektablebuf[MAX_SEEKPOINTS];
#define INPUT_CHUNKSIZE (32*1024)
/* 4608*4 = 18432 bytes per channel */
static int32_t decoded0[BLOCKS_PER_LOOP] IBSS_ATTR;
static int32_t decoded1[BLOCKS_PER_LOOP] IBSS_ATTR;
#define MAX_SUPPORTED_SEEKTABLE_SIZE 5000
/* Given an ape_ctx and a sample to seek to, return the file position
to the frame containing that sample, and the number of samples to
skip in that frame.
*/
bool ape_calc_seekpos(struct ape_ctx_t* ape_ctx,
uint32_t new_sample,
uint32_t* newframe,
uint32_t* filepos,
uint32_t* samplestoskip)
{
uint32_t n;
n = new_sample / ape_ctx->blocksperframe;
if (n >= ape_ctx->numseekpoints)
{
/* We don't have a seekpoint for that frame */
return false;
}
*newframe = n;
*filepos = ape_ctx->seektable[n];
*samplestoskip = new_sample - (n * ape_ctx->blocksperframe);
return true;
}
/* The resume offset is a value in bytes - we need to
turn it into a frame number and samplestoskip value */
void ape_resume(struct ape_ctx_t* ape_ctx, size_t resume_offset,
uint32_t* currentframe, uint32_t* samplesdone,
uint32_t* samplestoskip, int* firstbyte)
{
off_t newfilepos;
int64_t framesize;
int64_t offset;
*currentframe = 0;
*samplesdone = 0;
*samplestoskip = 0;
while ((*currentframe < ape_ctx->totalframes) &&
(*currentframe < ape_ctx->numseekpoints) &&
(resume_offset > ape_ctx->seektable[*currentframe]))
{
++*currentframe;
*samplesdone += ape_ctx->blocksperframe;
}
if ((*currentframe > 0) &&
(ape_ctx->seektable[*currentframe] > resume_offset)) {
--*currentframe;
*samplesdone -= ape_ctx->blocksperframe;
}
newfilepos = ape_ctx->seektable[*currentframe];
/* APE's bytestream is weird... */
*firstbyte = 3 - (newfilepos & 3);
newfilepos &= ~3;
ci->seek_buffer(newfilepos);
/* We estimate where we were in the current frame, based on the
byte offset */
if (*currentframe < (ape_ctx->totalframes - 1)) {
framesize = ape_ctx->seektable[*currentframe+1] - ape_ctx->seektable[*currentframe];
offset = resume_offset - ape_ctx->seektable[*currentframe];
*samplestoskip = (offset * ape_ctx->blocksperframe) / framesize;
}
}
/* this is the codec entry point */
enum codec_status codec_main(void)
{
struct ape_ctx_t ape_ctx;
uint32_t samplesdone;
uint32_t elapsedtime;
size_t bytesleft;
int retval;
uint32_t currentframe;
uint32_t newfilepos;
uint32_t samplestoskip;
int nblocks;
int bytesconsumed;
unsigned char* inbuffer;
uint32_t blockstodecode;
int res;
int firstbyte;
size_t resume_offset;
/* Generic codec initialisation */
ci->configure(CODEC_SET_FILEBUF_WATERMARK, 1024*512);
ci->configure(DSP_SET_SAMPLE_DEPTH, APE_OUTPUT_DEPTH-1);
next_track:
retval = CODEC_OK;
/* Remember the resume position - when the codec is opened, the
playback engine will reset it. */
resume_offset = ci->id3->offset;
if (codec_init()) {
LOGF("APE: Error initialising codec\n");
retval = CODEC_ERROR;
goto exit;
}
while (!*ci->taginfo_ready && !ci->stop_codec)
ci->sleep(1);
inbuffer = ci->request_buffer(&bytesleft, INPUT_CHUNKSIZE);
/* Read the file headers to populate the ape_ctx struct */
if (ape_parseheaderbuf(inbuffer,&ape_ctx) < 0) {
LOGF("APE: Error reading header\n");
retval = CODEC_ERROR;
goto exit;
}
/* Initialise the seektable for this file */
ape_ctx.seektable = seektablebuf;
ape_ctx.numseekpoints = MIN(MAX_SEEKPOINTS,ape_ctx.numseekpoints);
ci->advance_buffer(ape_ctx.seektablefilepos);
/* The seektable may be bigger than the guard buffer (32KB), so we
do a read() */
ci->read_filebuf(ape_ctx.seektable, ape_ctx.numseekpoints * sizeof(uint32_t));
#ifdef ROCKBOX_BIG_ENDIAN
/* Byte-swap the little-endian seekpoints */
{
uint32_t i;
for(i = 0; i < ape_ctx.numseekpoints; i++)
ape_ctx.seektable[i] = swap32(ape_ctx.seektable[i]);
}
#endif
/* Now advance the file position to the first frame */
ci->advance_buffer(ape_ctx.firstframe -
(ape_ctx.seektablefilepos +
ape_ctx.numseekpoints * sizeof(uint32_t)));
ci->configure(DSP_SWITCH_FREQUENCY, ape_ctx.samplerate);
ci->configure(DSP_SET_STEREO_MODE, ape_ctx.channels == 1 ?
STEREO_MONO : STEREO_NONINTERLEAVED);
codec_set_replaygain(ci->id3);
/* The main decoding loop */
if (resume_offset) {
/* The resume offset is a value in bytes - we need to
turn it into a frame number and samplestoskip value */
ape_resume(&ape_ctx, resume_offset,
&currentframe, &samplesdone, &samplestoskip, &firstbyte);
} else {
currentframe = 0;
samplesdone = 0;
samplestoskip = 0;
firstbyte = 3; /* Take account of the little-endian 32-bit byte ordering */
}
/* Initialise the buffer */
inbuffer = ci->request_buffer(&bytesleft, INPUT_CHUNKSIZE);
/* The main decoding loop - we decode the frames a small chunk at a time */
while (currentframe < ape_ctx.totalframes)
{
frame_start:
/* Calculate how many blocks there are in this frame */
if (currentframe == (ape_ctx.totalframes - 1))
nblocks = ape_ctx.finalframeblocks;
else
nblocks = ape_ctx.blocksperframe;
ape_ctx.currentframeblocks = nblocks;
/* Initialise the frame decoder */
init_frame_decoder(&ape_ctx, inbuffer, &firstbyte, &bytesconsumed);
ci->advance_buffer(bytesconsumed);
inbuffer = ci->request_buffer(&bytesleft, INPUT_CHUNKSIZE);
/* Decode the frame a chunk at a time */
while (nblocks > 0)
{
ci->yield();
if (ci->stop_codec || ci->new_track) {
goto done;
}
/* Deal with any pending seek requests */
if (ci->seek_time)
{
if (ape_calc_seekpos(&ape_ctx,
((ci->seek_time-1)/10) * (ci->id3->frequency/100),
&currentframe,
&newfilepos,
&samplestoskip))
{
samplesdone = currentframe * ape_ctx.blocksperframe;
/* APE's bytestream is weird... */
firstbyte = 3 - (newfilepos & 3);
newfilepos &= ~3;
ci->seek_buffer(newfilepos);
inbuffer = ci->request_buffer(&bytesleft, INPUT_CHUNKSIZE);
ci->seek_complete();
goto frame_start; /* Sorry... */
}
ci->seek_complete();
}
blockstodecode = MIN(BLOCKS_PER_LOOP, nblocks);
if ((res = decode_chunk(&ape_ctx, inbuffer, &firstbyte,
&bytesconsumed,
decoded0, decoded1,
blockstodecode)) < 0)
{
/* Frame decoding error, abort */
LOGF("APE: Frame %d, error %d\n",currentframe,res);
retval = CODEC_ERROR;
goto done;
}
ci->yield();
if (samplestoskip > 0) {
if (samplestoskip < blockstodecode) {
ci->pcmbuf_insert(decoded0 + samplestoskip,
decoded1 + samplestoskip,
blockstodecode - samplestoskip);
samplestoskip = 0;
} else {
samplestoskip -= blockstodecode;
}
} else {
ci->pcmbuf_insert(decoded0, decoded1, blockstodecode);
}
samplesdone += blockstodecode;
if (!samplestoskip) {
/* Update the elapsed-time indicator */
elapsedtime = (samplesdone*10)/(ape_ctx.samplerate/100);
ci->set_elapsed(elapsedtime);
}
ci->advance_buffer(bytesconsumed);
inbuffer = ci->request_buffer(&bytesleft, INPUT_CHUNKSIZE);
/* Decrement the block count */
nblocks -= blockstodecode;
}
currentframe++;
}
retval = CODEC_OK;
done:
LOGF("APE: Decoded %ld samples\n",samplesdone);
if (ci->request_next_track())
goto next_track;
exit:
return retval;
}