aboutsummaryrefslogtreecommitdiffhomepage
path: root/libmpdemux/demux_mpc.c
blob: 234eed45da07b73e59bcaa0417e356e1309daa9d (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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/*
 * demuxer for Musepack v7 bitstream
 * copyright (c) 2005 Reimar Doeffinger <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)
 *
 * This file is part of MPlayer.
 *
 * MPlayer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * MPlayer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "mp_msg.h"
#include "libavutil/common.h"
#include "mpbswap.h"
#include "stream/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 & SEEK_FACTOR)
    target *= priv->length;
  if (!(flags & SEEK_ABSOLUTE))
    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;

  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;
}


const 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
};