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/**
* Demuxer for Musepack v7 bitstream
* by Reimar Döffinger <Reimar.Doeffinger@stud.uni-karlsruhe.de>
* This code may be be relicensed under the terms of the GNU LGPL when it
* becomes part of the FFmpeg project (ffmpeg.org)
*/
#include "config.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "mp_msg.h"
#include "bswap.h"
#include "stream.h"
#include "demuxer.h"
#include "stheader.h"
#define HDR_SIZE (6 * 4)
typedef struct da_priv {
float last_pts;
float pts_per_packet;
uint32_t dword;
int pos;
float length;
} da_priv_t;
static uint32_t get_bits(da_priv_t* priv, stream_t* s, int bits) {
uint32_t out = priv->dword;
uint32_t mask = (1 << bits) - 1;
priv->pos += bits;
if (priv->pos < 32) {
out >>= (32 - priv->pos);
}
else {
stream_read(s, (void *)&priv->dword, 4);
priv->dword = le2me_32(priv->dword);
priv->pos -= 32;
if (priv->pos) {
out <<= priv->pos;
out |= priv->dword >> (32 - priv->pos);
}
}
return out & mask;
}
static int demux_mpc_check(demuxer_t* demuxer) {
stream_t *s = demuxer->stream;
uint8_t hdr[HDR_SIZE];
int i;
if (stream_read(s, hdr, HDR_SIZE) != HDR_SIZE)
return 0;
for (i = 0; i < 30000 && !s->eof; i++) {
if (hdr[0] == 'M' && hdr[1] == 'P' && hdr[2] == '+')
break;
memmove(hdr, &hdr[1], HDR_SIZE - 1);
stream_read(s, &hdr[HDR_SIZE - 1], 1);
}
if (hdr[0] != 'M' || hdr[1] != 'P' || hdr[2] != '+')
return 0;
demuxer->movi_start = stream_tell(s) - HDR_SIZE;
demuxer->movi_end = s->end_pos;
demuxer->priv = malloc(HDR_SIZE);
memcpy(demuxer->priv, hdr, HDR_SIZE);
return DEMUXER_TYPE_MPC;
}
static demuxer_t *demux_mpc_open(demuxer_t* demuxer) {
float seconds = 0;
stream_t *s = demuxer->stream;
sh_audio_t* sh_audio;
da_priv_t* priv = demuxer->priv;
sh_audio = new_sh_audio(demuxer,0);
{
char *wf = calloc(1, sizeof(WAVEFORMATEX) + HDR_SIZE);
char *header = &wf[sizeof(WAVEFORMATEX)];
const int freqs[4] = {44100, 48000, 37800, 32000};
int frames;
sh_audio->format = mmioFOURCC('M', 'P', 'C', ' ');
memcpy(header, priv, HDR_SIZE);
free(priv);
frames = header[4] | header[5] << 8 | header[6] << 16 | header[7] << 24;
sh_audio->wf = (WAVEFORMATEX *)wf;
sh_audio->wf->wFormatTag = sh_audio->format;
sh_audio->wf->nChannels = 2;
sh_audio->wf->nSamplesPerSec = freqs[header[10] & 3];
sh_audio->wf->nBlockAlign = 32 * 36;
sh_audio->wf->wBitsPerSample = 16;
seconds = 1152 * frames / (float)sh_audio->wf->nSamplesPerSec;
if (demuxer->movi_end > demuxer->movi_start && seconds > 1)
sh_audio->wf->nAvgBytesPerSec = (demuxer->movi_end - demuxer->movi_start) / seconds;
else
sh_audio->wf->nAvgBytesPerSec = 32 * 1024; // dummy to make mencoder not hang
sh_audio->wf->cbSize = HDR_SIZE;
demuxer->movi_start = stream_tell(s);
demuxer->movi_end = s->end_pos;
}
priv = malloc(sizeof(da_priv_t));
priv->last_pts = -1;
priv->pts_per_packet = (32 * 36) / (float)sh_audio->wf->nSamplesPerSec;
priv->length = seconds;
priv->dword = 0;
priv->pos = 32; // empty bit buffer
get_bits(priv, s, 8); // discard first 8 bits
demuxer->priv = priv;
demuxer->audio->id = 0;
demuxer->audio->sh = sh_audio;
sh_audio->ds = demuxer->audio;
sh_audio->samplerate = sh_audio->wf->nSamplesPerSec;
sh_audio->i_bps = sh_audio->wf->nAvgBytesPerSec;
sh_audio->audio.dwSampleSize = 0;
sh_audio->audio.dwScale = 32 * 36;
sh_audio->audio.dwRate = sh_audio->samplerate;
return demuxer;
}
static int demux_mpc_fill_buffer(demuxer_t *demux, demux_stream_t *ds) {
int l;
int bit_len;
demux_packet_t* dp;
sh_audio_t* sh_audio = ds->sh;
da_priv_t* priv = demux->priv;
stream_t* s = demux->stream;
sh_audio = ds->sh;
if (s->eof)
return 0;
bit_len = get_bits(priv, s, 20);
dp = new_demux_packet((bit_len + 7) / 8);
for (l = 0; l < (bit_len / 8); l++)
dp->buffer[l] = get_bits(priv, s, 8);
bit_len %= 8;
if (bit_len)
dp->buffer[l] = get_bits(priv, s, bit_len) << (8 - bit_len);
if (priv->last_pts < 0)
priv->last_pts = 0;
else
priv->last_pts += priv->pts_per_packet;
dp->pts = priv->last_pts;
ds_add_packet(ds, dp);
return 1;
}
static void demux_mpc_seek(demuxer_t *demuxer,float rel_seek_secs,float audio_delay,int flags){
sh_audio_t* sh_audio = demuxer->audio->sh;
da_priv_t* priv = demuxer->priv;
stream_t* s = demuxer->stream;
float target = rel_seek_secs;
if (flags & 2)
target *= priv->length;
if (!(flags & 1))
target += priv->last_pts;
if (target < priv->last_pts) {
stream_seek(s, demuxer->movi_start);
priv->pos = 32; // empty bit buffer
get_bits(priv, s, 8); // discard first 8 bits
priv->last_pts = 0;
}
while (target > priv->last_pts) {
int bit_len = get_bits(priv, s, 20);
if (bit_len > 32) {
stream_skip(s, bit_len / 32 * 4 - 4);
get_bits(priv, s, 32); // make sure dword is reloaded
}
get_bits(priv, s, bit_len % 32);
priv->last_pts += priv->pts_per_packet;
if (s->eof) break;
}
if (!sh_audio) return;
}
static void demux_close_mpc(demuxer_t* demuxer) {
da_priv_t* priv = demuxer->priv;
if(!priv)
return;
free(priv);
}
static int demux_mpc_control(demuxer_t *demuxer,int cmd, void *arg){
da_priv_t* priv = demuxer->priv;
switch (cmd) {
case DEMUXER_CTRL_GET_TIME_LENGTH:
if (priv->length < 1) return DEMUXER_CTRL_DONTKNOW;
*((double *)arg) = priv->length;
return DEMUXER_CTRL_OK;
case DEMUXER_CTRL_GET_PERCENT_POS:
if (priv->length < 1) return DEMUXER_CTRL_DONTKNOW;
*((int *)arg) = priv->last_pts * 100 / priv->length;
return DEMUXER_CTRL_OK;
}
return DEMUXER_CTRL_NOTIMPL;
}
demuxer_desc_t demuxer_desc_mpc = {
"Musepack demuxer",
"mpc",
"MPC",
"Reza Jelveh, Reimar Doeffinger",
"supports v7 bitstream only",
DEMUXER_TYPE_MPC,
0, // unsafe autodetect
demux_mpc_check,
demux_mpc_fill_buffer,
demux_mpc_open,
demux_close_mpc,
demux_mpc_seek,
demux_mpc_control
};
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