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/**
* Musepack audio files decoder for MPlayer
* by Reza Jelveh <reza.jelveh@tuhh.de> and
* Reimar Döffinger <Reimar.Doeffinger@stud.uni-karlsruhe.de>
* License: GPL
* This code may be be relicensed under the terms of the GNU LGPL when it
* becomes part of the FFmpeg project (ffmpeg.org)
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "config.h"
#include "ad_internal.h"
#include "libaf/af_format.h"
#include "libvo/fastmemcpy.h"
static ad_info_t info =
{
"Musepack audio decoder",
"mpcdec",
"Reza Jelveh and Reimar Döffinger",
"",
""
};
LIBAD_EXTERN(libmusepack)
#include <mpcdec/mpcdec.h>
// BUFFER_LENGTH is in MPC_SAMPLE_FORMAT units
#define MAX_FRAMESIZE (4 * MPC_DECODER_BUFFER_LENGTH)
//! this many frames should decode good after seeking
#define MIN_SEEK_GOOD 5
//! how many frames to discard at most after seeking
#define MAX_SEEK_DISCARD 50
typedef struct context_s {
char *header;
int header_len;
sh_audio_t *sh;
uint32_t pos;
mpc_decoder decoder;
} context_t;
/**
* \brief mpc_reader callback function for reading the header
*/
static mpc_int32_t cb_read(void *data, void *buf, mpc_int32_t size) {
context_t *d = (context_t *)data;
char *p = (char *)buf;
int s = size;
if (d->pos < d->header_len) {
if (s > d->header_len - d->pos)
s = d->header_len - d->pos;
memcpy(p, &d->header[d->pos], s);
} else
s = 0;
memset(&p[s], 0, size - s);
d->pos += size;
return size;
}
/**
* \brief dummy mpc_reader callback function for seeking
*/
static mpc_bool_t cb_seek(void *data, mpc_int32_t offset ) {
context_t *d = (context_t *)data;
d->pos = offset;
return 1;
}
/**
* \brief dummy mpc_reader callback function for getting stream position
*/
static mpc_int32_t cb_tell(void *data) {
context_t *d = (context_t *)data;
return d->pos;
}
/**
* \brief dummy mpc_reader callback function for getting stream length
*/
static mpc_int32_t cb_get_size(void *data) {
return 1 << 30;
}
/**
* \brief mpc_reader callback function, we cannot seek.
*/
static mpc_bool_t cb_canseek(void *data) {
return 0;
}
mpc_reader header_reader = {
.read = cb_read, .seek = cb_seek, .tell = cb_tell,
.get_size = cb_get_size, .canseek = cb_canseek
};
static int preinit(sh_audio_t *sh) {
sh->audio_out_minsize = MAX_FRAMESIZE;
return 1;
}
static void uninit(sh_audio_t *sh) {
if (sh->context)
free(sh->context);
sh->context = NULL;
}
static int init(sh_audio_t *sh) {
mpc_streaminfo info;
context_t *cd = malloc(sizeof(context_t));
if (!sh->wf || (sh->wf->cbSize < 6 * 4)) {
mp_msg(MSGT_DECAUDIO, MSGL_FATAL, "Missing extradata!\n");
return 0;
}
cd->header = (char *)sh->wf;
cd->header = &cd->header[sizeof(WAVEFORMATEX)];
cd->header_len = sh->wf->cbSize;
cd->sh = sh;
cd->pos = 0;
sh->context = (char *)cd;
/* read file's streaminfo data */
mpc_streaminfo_init(&info);
header_reader.data = cd;
if (mpc_streaminfo_read(&info, &header_reader) != ERROR_CODE_OK) {
mp_msg(MSGT_DECAUDIO, MSGL_FATAL, "Not a valid musepack file.\n");
return 0;
}
// this value is nonsense, since it relies on the get_size function.
// use the value from the demuxer instead.
// sh->i_bps = info.average_bitrate / 8;
sh->channels = info.channels;
sh->samplerate = info.sample_freq;
sh->samplesize = 4;
sh->sample_format =
#if MPC_SAMPLE_FORMAT == float
AF_FORMAT_FLOAT_NE;
#elif MPC_SAMPLE_FORMAT == mpc_int32_t
AF_FORMAT_S32_NE;
#else
#error musepack lib must use either float or mpc_int32_t sample format
#endif
mpc_decoder_setup(&cd->decoder, NULL);
mpc_decoder_set_streaminfo(&cd->decoder, &info);
return 1;
}
// FIXME: minlen is currently ignored
static int decode_audio(sh_audio_t *sh, unsigned char *buf,
int minlen, int maxlen) {
int status, len;
MPC_SAMPLE_FORMAT *sample_buffer = (MPC_SAMPLE_FORMAT *)buf;
mpc_uint32_t *packet = NULL;
context_t *cd = (context_t *) sh->context;
if (maxlen < MAX_FRAMESIZE) {
mp_msg(MSGT_DECAUDIO, MSGL_V, "maxlen too small in decode_audio\n");
return -1;
}
len = ds_get_packet(sh->ds, (unsigned char **)&packet);
if (len <= 0) return -1;
status = mpc_decoder_decode_frame(&cd->decoder, packet, len, sample_buffer);
if (status == -1) // decode error
mp_msg(MSGT_DECAUDIO, MSGL_FATAL, "Error decoding file.\n");
if (status <= 0) // error or EOF
return -1;
status = MPC_FRAME_LENGTH * sh->channels; // one sample per channel
#if MPC_SAMPLE_FORMAT == float || MPC_SAMPLE_FORMAT == mpc_int32_t
status *= 4;
#else
// should not happen
status *= 2;
#endif
return status;
}
/**
* \brief check if the decoded values are in a sane range
* \param buf decoded buffer
* \param len length of buffer in bytes
* \return 1 if all values are in (-1.01, 1.01) range, 0 otherwise
*/
static int check_clip(void *buf, int len) {
#if MPC_SAMPLE_FORMAT == float
float *p = buf;
if (len < 4) return 1;
len = -len / 4;
p = &p[-len];
do {
if (p[len] < -1 || p[len] > 1) return 0;
} while (++len);
#endif
return 1;
}
static int control(sh_audio_t *sh, int cmd, void* arg, ...) {
if (cmd == ADCTRL_RESYNC_STREAM) {
unsigned char *buf = malloc(MAX_FRAMESIZE);
int i;
int nr_ok = 0;
for (i = 0; i < MAX_SEEK_DISCARD; i++) {
int len = decode_audio(sh, buf, 0, MAX_FRAMESIZE);
if (check_clip(buf, len)) nr_ok++; else nr_ok = 0;
if (nr_ok > MIN_SEEK_GOOD) break;
}
free(buf);
}
return CONTROL_UNKNOWN;
}
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