apps/codecs/aac.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2005 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"
#include "libm4a/m4a.h"
#include "libfaad/common.h"
#include "libfaad/structs.h"
#include "libfaad/decoder.h"

CODEC_HEADER

#ifndef SIMULATOR
extern char iramcopy[];
extern char iramstart[];
extern char iramend[];
#endif

struct codec_api* rb;
struct codec_api* ci;

/* this is the codec entry point */
enum codec_status codec_start(struct codec_api* api)
{
    size_t n;
    static demux_res_t demux_res;
    stream_t input_stream;
    uint32_t samplesdone;
    uint32_t elapsedtime;
    uint32_t sample_duration;
    uint32_t sample_byte_size;
    int samplesdecoded;
    unsigned int i;
    unsigned char* buffer;
    static NeAACDecFrameInfo frameInfo;
    NeAACDecHandle hDecoder;
    int err;
    int16_t* decodedbuffer;

    /* Generic codec initialisation */
    rb = api;
    ci = api;

#ifndef SIMULATOR
    rb->memcpy(iramstart, iramcopy, iramend-iramstart);
#endif

    ci->configure(CODEC_SET_FILEBUF_CHUNKSIZE, (int *)(1024*16));
    ci->configure(CODEC_SET_FILEBUF_WATERMARK, (int *)(1024*512));

    ci->configure(CODEC_DSP_ENABLE, (bool *)true);
    ci->configure(DSP_DITHER, (bool *)false);
    ci->configure(DSP_SET_STEREO_MODE, (int *)STEREO_NONINTERLEAVED);
    ci->configure(DSP_SET_SAMPLE_DEPTH, (int *)(29));

    next_track:

    if (codec_init(api)) {
        LOGF("FAAD: Error initialising codec\n");
        err = CODEC_ERROR;
        goto exit;
    }

    while (!rb->taginfo_ready)
        rb->yield();
  
    ci->configure(DSP_SET_FREQUENCY, (long *)(rb->id3->frequency));

    stream_create(&input_stream,ci);

    /* if qtmovie_read returns successfully, the stream is up to
     * the movie data, which can be used directly by the decoder */
    if (!qtmovie_read(&input_stream, &demux_res)) {
        LOGF("FAAD: Error initialising file\n");
        err = CODEC_ERROR;
        goto exit;
    }

    /* initialise the sound converter */
    hDecoder = NULL;
    hDecoder = NeAACDecOpen();

    if (!hDecoder) {
        LOGF("FAAD: Error opening decoder\n");
        err = CODEC_ERROR;
        goto exit;
    }

    NeAACDecConfigurationPtr conf = NeAACDecGetCurrentConfiguration(hDecoder);
    conf->outputFormat = FAAD_FMT_24BIT; /* irrelevant, we don't convert */
    NeAACDecSetConfiguration(hDecoder, conf);

    unsigned long s=0;
    unsigned char c=0;

    err = NeAACDecInit2(hDecoder, demux_res.codecdata,demux_res.codecdata_len, &s, &c);
    if (err) {
        LOGF("FAAD: Error initialising decoder: %d, type=%d\n", err,hDecoder->object_type);
        err = CODEC_ERROR;
        goto exit;
    }

    ci->id3->frequency=s;

    i=0;
    samplesdone=0;
    /* The main decoding loop */
    while (i < demux_res.num_sample_byte_sizes) {
        rb->yield();
        if (ci->stop_codec || ci->reload_codec) {
            break;
        }

        /* Deal with any pending seek requests */
        if (ci->seek_time) {
            if (alac_seek(&demux_res, &input_stream,
                          ((ci->seek_time-1)/10) * (ci->id3->frequency/100),
                          &samplesdone, (int *)&i)) {
                elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
                ci->set_elapsed(elapsedtime);
            }
            ci->seek_complete();
        }

        /* Lookup the length (in samples and bytes) of block i */
        if (!get_sample_info(&demux_res, i, &sample_duration, 
                             &sample_byte_size)) {
            LOGF("AAC: Error in get_sample_info\n");
            err = CODEC_ERROR;
            goto exit;
        }

        /* Request the required number of bytes from the input buffer */
        buffer=ci->request_buffer((long*)&n,sample_byte_size);

        /* Decode one block - returned samples will be host-endian */
        rb->yield();
        decodedbuffer = NeAACDecDecode(hDecoder, &frameInfo, buffer, n);
        /* ignore decodedbuffer return value, we access samples in the
           decoder struct directly */
        if (frameInfo.error > 0) {
             LOGF("FAAD: decoding error \"%s\"\n", NeAACDecGetErrorMessage(frameInfo.error));
             err = CODEC_ERROR;
             goto exit;
        }

        /* Get the number of decoded samples */
        samplesdecoded=frameInfo.samples;

        /* Advance codec buffer */
        ci->advance_buffer(n);

        /* Output the audio */
        rb->yield();
        while (!rb->pcmbuf_insert_split(hDecoder->time_out[0],
                                        hDecoder->time_out[1],
                                        frameInfo.samples*2))
            rb->yield();

        /* Update the elapsed-time indicator */
        samplesdone+=sample_duration;
        elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
        ci->set_elapsed(elapsedtime);

        /* Keep track of current position - for resuming */
        ci->set_offset(elapsedtime);

        i++;
    }

    LOGF("AAC: Decoded %d samples\n",samplesdone);

    if (ci->request_next_track())
        goto next_track;

    err = CODEC_OK;
exit:
    return err;
}