mmf.c
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1 /*
2  * Yamaha SMAF format
3  * Copyright (c) 2005 Vidar Madsen
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
23 #include "avformat.h"
24 #include "internal.h"
25 #include "avio_internal.h"
26 #include "pcm.h"
27 #include "riff.h"
28 
29 typedef struct {
30  int64_t atrpos, atsqpos, awapos;
31  int64_t data_size;
32 } MMFContext;
33 
34 static const int mmf_rates[] = { 4000, 8000, 11025, 22050, 44100 };
35 
36 static int mmf_rate(int code)
37 {
38  if((code < 0) || (code > 4))
39  return -1;
40  return mmf_rates[code];
41 }
42 
43 #if CONFIG_MMF_MUXER
44 static int mmf_rate_code(int rate)
45 {
46  int i;
47  for(i = 0; i < 5; i++)
48  if(mmf_rates[i] == rate)
49  return i;
50  return -1;
51 }
52 
53 /* Copy of end_tag() from avienc.c, but for big-endian chunk size */
54 static void end_tag_be(AVIOContext *pb, int64_t start)
55 {
56  int64_t pos;
57 
58  pos = avio_tell(pb);
59  avio_seek(pb, start - 4, SEEK_SET);
60  avio_wb32(pb, (uint32_t)(pos - start));
61  avio_seek(pb, pos, SEEK_SET);
62 }
63 
64 static int mmf_write_header(AVFormatContext *s)
65 {
66  MMFContext *mmf = s->priv_data;
67  AVIOContext *pb = s->pb;
68  int64_t pos;
69  int rate;
70 
71  rate = mmf_rate_code(s->streams[0]->codec->sample_rate);
72  if(rate < 0) {
73  av_log(s, AV_LOG_ERROR, "Unsupported sample rate %d\n", s->streams[0]->codec->sample_rate);
74  return -1;
75  }
76 
77  ffio_wfourcc(pb, "MMMD");
78  avio_wb32(pb, 0);
79  pos = ff_start_tag(pb, "CNTI");
80  avio_w8(pb, 0); /* class */
81  avio_w8(pb, 0); /* type */
82  avio_w8(pb, 0); /* code type */
83  avio_w8(pb, 0); /* status */
84  avio_w8(pb, 0); /* counts */
85  avio_write(pb, "VN:libavcodec,", sizeof("VN:libavcodec,") -1); /* metadata ("ST:songtitle,VN:version,...") */
86  end_tag_be(pb, pos);
87 
88  avio_write(pb, "ATR\x00", 4);
89  avio_wb32(pb, 0);
90  mmf->atrpos = avio_tell(pb);
91  avio_w8(pb, 0); /* format type */
92  avio_w8(pb, 0); /* sequence type */
93  avio_w8(pb, (0 << 7) | (1 << 4) | rate); /* (channel << 7) | (format << 4) | rate */
94  avio_w8(pb, 0); /* wave base bit */
95  avio_w8(pb, 2); /* time base d */
96  avio_w8(pb, 2); /* time base g */
97 
98  ffio_wfourcc(pb, "Atsq");
99  avio_wb32(pb, 16);
100  mmf->atsqpos = avio_tell(pb);
101  /* Will be filled on close */
102  avio_write(pb, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16);
103 
104  mmf->awapos = ff_start_tag(pb, "Awa\x01");
105 
106  avpriv_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);
107 
108  avio_flush(pb);
109 
110  return 0;
111 }
112 
113 static int mmf_write_packet(AVFormatContext *s, AVPacket *pkt)
114 {
115  AVIOContext *pb = s->pb;
116  avio_write(pb, pkt->data, pkt->size);
117  return 0;
118 }
119 
120 /* Write a variable-length symbol */
121 static void put_varlength(AVIOContext *pb, int val)
122 {
123  if(val < 128)
124  avio_w8(pb, val);
125  else {
126  val -= 128;
127  avio_w8(pb, 0x80 | val >> 7);
128  avio_w8(pb, 0x7f & val);
129  }
130 }
131 
132 static int mmf_write_trailer(AVFormatContext *s)
133 {
134  AVIOContext *pb = s->pb;
135  MMFContext *mmf = s->priv_data;
136  int64_t pos, size;
137  int gatetime;
138 
139  if (s->pb->seekable) {
140  /* Fill in length fields */
141  end_tag_be(pb, mmf->awapos);
142  end_tag_be(pb, mmf->atrpos);
143  end_tag_be(pb, 8);
144 
145  pos = avio_tell(pb);
146  size = pos - mmf->awapos;
147 
148  /* Fill Atsq chunk */
149  avio_seek(pb, mmf->atsqpos, SEEK_SET);
150 
151  /* "play wav" */
152  avio_w8(pb, 0); /* start time */
153  avio_w8(pb, 1); /* (channel << 6) | wavenum */
154  gatetime = size * 500 / s->streams[0]->codec->sample_rate;
155  put_varlength(pb, gatetime); /* duration */
156 
157  /* "nop" */
158  put_varlength(pb, gatetime); /* start time */
159  avio_write(pb, "\xff\x00", 2); /* nop */
160 
161  /* "end of sequence" */
162  avio_write(pb, "\x00\x00\x00\x00", 4);
163 
164  avio_seek(pb, pos, SEEK_SET);
165 
166  avio_flush(pb);
167  }
168  return 0;
169 }
170 #endif /* CONFIG_MMF_MUXER */
171 
172 static int mmf_probe(AVProbeData *p)
173 {
174  /* check file header */
175  if (p->buf[0] == 'M' && p->buf[1] == 'M' &&
176  p->buf[2] == 'M' && p->buf[3] == 'D' &&
177  p->buf[8] == 'C' && p->buf[9] == 'N' &&
178  p->buf[10] == 'T' && p->buf[11] == 'I')
179  return AVPROBE_SCORE_MAX;
180  else
181  return 0;
182 }
183 
184 /* mmf input */
186 {
187  MMFContext *mmf = s->priv_data;
188  unsigned int tag;
189  AVIOContext *pb = s->pb;
190  AVStream *st;
191  int64_t size;
192  int rate, params;
193 
194  tag = avio_rl32(pb);
195  if (tag != MKTAG('M', 'M', 'M', 'D'))
196  return -1;
197  avio_skip(pb, 4); /* file_size */
198 
199  /* Skip some unused chunks that may or may not be present */
200  for(;; avio_skip(pb, size)) {
201  tag = avio_rl32(pb);
202  size = avio_rb32(pb);
203  if(tag == MKTAG('C','N','T','I')) continue;
204  if(tag == MKTAG('O','P','D','A')) continue;
205  break;
206  }
207 
208  /* Tag = "ATRx", where "x" = track number */
209  if ((tag & 0xffffff) == MKTAG('M', 'T', 'R', 0)) {
210  av_log(s, AV_LOG_ERROR, "MIDI like format found, unsupported\n");
211  return -1;
212  }
213  if ((tag & 0xffffff) != MKTAG('A', 'T', 'R', 0)) {
214  av_log(s, AV_LOG_ERROR, "Unsupported SMAF chunk %08x\n", tag);
215  return -1;
216  }
217 
218  avio_r8(pb); /* format type */
219  avio_r8(pb); /* sequence type */
220  params = avio_r8(pb); /* (channel << 7) | (format << 4) | rate */
221  rate = mmf_rate(params & 0x0f);
222  if(rate < 0) {
223  av_log(s, AV_LOG_ERROR, "Invalid sample rate\n");
224  return -1;
225  }
226  avio_r8(pb); /* wave base bit */
227  avio_r8(pb); /* time base d */
228  avio_r8(pb); /* time base g */
229 
230  /* Skip some unused chunks that may or may not be present */
231  for(;; avio_skip(pb, size)) {
232  tag = avio_rl32(pb);
233  size = avio_rb32(pb);
234  if(tag == MKTAG('A','t','s','q')) continue;
235  if(tag == MKTAG('A','s','p','I')) continue;
236  break;
237  }
238 
239  /* Make sure it's followed by an Awa chunk, aka wave data */
240  if ((tag & 0xffffff) != MKTAG('A', 'w', 'a', 0)) {
241  av_log(s, AV_LOG_ERROR, "Unexpected SMAF chunk %08x\n", tag);
242  return -1;
243  }
244  mmf->data_size = size;
245 
246  st = avformat_new_stream(s, NULL);
247  if (!st)
248  return AVERROR(ENOMEM);
249 
252  st->codec->sample_rate = rate;
253  st->codec->channels = 1;
255  st->codec->bits_per_coded_sample = 4;
257 
258  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
259 
260  return 0;
261 }
262 
263 #define MAX_SIZE 4096
264 
266  AVPacket *pkt)
267 {
268  MMFContext *mmf = s->priv_data;
269  int ret, size;
270 
271  if (s->pb->eof_reached)
272  return AVERROR(EIO);
273 
274  size = MAX_SIZE;
275  if(size > mmf->data_size)
276  size = mmf->data_size;
277 
278  if(!size)
279  return AVERROR(EIO);
280 
281  if (av_new_packet(pkt, size))
282  return AVERROR(EIO);
283  pkt->stream_index = 0;
284 
285  ret = avio_read(s->pb, pkt->data, pkt->size);
286  if (ret < 0)
287  av_free_packet(pkt);
288 
289  mmf->data_size -= ret;
290 
291  pkt->size = ret;
292  return ret;
293 }
294 
295 #if CONFIG_MMF_DEMUXER
296 AVInputFormat ff_mmf_demuxer = {
297  .name = "mmf",
298  .long_name = NULL_IF_CONFIG_SMALL("Yamaha SMAF"),
299  .priv_data_size = sizeof(MMFContext),
304 };
305 #endif
306 #if CONFIG_MMF_MUXER
307 AVOutputFormat ff_mmf_muxer = {
308  .name = "mmf",
309  .long_name = NULL_IF_CONFIG_SMALL("Yamaha SMAF"),
310  .mime_type = "application/vnd.smaf",
311  .extensions = "mmf",
312  .priv_data_size = sizeof(MMFContext),
313  .audio_codec = AV_CODEC_ID_ADPCM_YAMAHA,
314  .video_codec = AV_CODEC_ID_NONE,
315  .write_header = mmf_write_header,
316  .write_packet = mmf_write_packet,
317  .write_trailer = mmf_write_trailer,
318 };
319 #endif