rockbox/apps/codecs/ape.c
Dave Chapman 7b1d90a851 Seeking and resume support for Monkey's Audio
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13597 a1c6a512-1295-4272-9138-f99709370657
2007-06-08 22:35:26 +00:00

334 lines
10 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 Dave Chapman
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* 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(CODEC_SET_FILEBUF_CHUNKSIZE, 1024*128);
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;
}
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)));
while (!*ci->taginfo_ready && !ci->stop_codec)
ci->sleep(1);
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;
}