summaryrefslogtreecommitdiffstats
path: root/libmpdemux/demux_mpc.c
blob: aae780943d58e60245f8cb824281dfca741b7525 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/**
 * 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;
  uint32_t dword;
  int pos;
} da_priv_t;

extern void free_sh_audio(sh_audio_t* sh);

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_open(demuxer_t* demuxer) {
  stream_t *s = demuxer->stream;
  sh_audio_t* sh_audio;
  uint8_t hdr[HDR_SIZE];
  da_priv_t* priv;
  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;

  sh_audio = new_sh_audio(demuxer,0);

  {
    char *wf = (char *)calloc(1, sizeof(WAVEFORMATEX) + HDR_SIZE);
    char *header = &wf[sizeof(WAVEFORMATEX)];
    const int freqs[4] = {44100, 48000, 37800, 32000};
    sh_audio->format = mmioFOURCC('M', 'P', 'C', ' ');
    memcpy(header, hdr, HDR_SIZE);
    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;
    sh_audio->wf->nAvgBytesPerSec = 128 * 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 = (da_priv_t *)malloc(sizeof(da_priv_t));
  priv->last_pts = -1;
  priv->dword = 0;
  priv->pos = 0;
  stream_read(s, (void *)&priv->dword, 4);
  priv->pos = 8;
  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_TYPE_MPC;
}

static int demux_mpc_fill_buffer(demux_stream_t *ds, demux_stream_t *dsds) {
  int l;
  int bit_len;
  demux_packet_t* dp;
  sh_audio_t* sh_audio = ds->sh;
  demuxer_t* demux = ds->demuxer;
  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 += (36 * 32) / (float)sh_audio->samplerate;
  ds->pts = priv->last_pts - (ds_tell_pts(demux->audio) -
              sh_audio->a_in_buffer_len)/(float)sh_audio->i_bps;
  ds_add_packet(ds, dp);
  return 1;
}

static void demux_mpc_seek(demuxer_t *demuxer,float rel_seek_secs,int flags){
// TODO
}

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){
  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_open,
  demux_mpc_fill_buffer,
  NULL,
  demux_close_mpc,
  demux_mpc_seek,
  demux_mpc_control
};