FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
mmf.c
Go to the documentation of this file.
1 /*
2  * Yamaha SMAF format
3  * Copyright (c) 2005 Vidar Madsen
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 "rawenc.h"
28 #include "riff.h"
29 
30 typedef struct {
31  int64_t atrpos, atsqpos, awapos;
32  int64_t data_end;
33  int stereo;
34 } MMFContext;
35 
36 static const int mmf_rates[] = { 4000, 8000, 11025, 22050, 44100 };
37 
38 static int mmf_rate(int code)
39 {
40  if((code < 0) || (code > 4))
41  return -1;
42  return mmf_rates[code];
43 }
44 
45 #if CONFIG_MMF_MUXER
46 static int mmf_rate_code(int rate)
47 {
48  int i;
49  for(i = 0; i < 5; i++)
50  if(mmf_rates[i] == rate)
51  return i;
52  return -1;
53 }
54 
55 /* Copy of end_tag() from avienc.c, but for big-endian chunk size */
56 static void end_tag_be(AVIOContext *pb, int64_t start)
57 {
58  int64_t pos;
59 
60  pos = avio_tell(pb);
61  avio_seek(pb, start - 4, SEEK_SET);
62  avio_wb32(pb, (uint32_t)(pos - start));
63  avio_seek(pb, pos, SEEK_SET);
64 }
65 
66 static int mmf_write_header(AVFormatContext *s)
67 {
68  MMFContext *mmf = s->priv_data;
69  AVIOContext *pb = s->pb;
70  int64_t pos;
71  int rate;
72  const char *version = s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT ?
73  "VN:Lavf," :
74  "VN:"LIBAVFORMAT_IDENT",";
75 
76  rate = mmf_rate_code(s->streams[0]->codec->sample_rate);
77  if(rate < 0) {
78  av_log(s, AV_LOG_ERROR, "Unsupported sample rate %d, supported are 4000, 8000, 11025, 22050 and 44100\n", s->streams[0]->codec->sample_rate);
79  return AVERROR(EINVAL);
80  }
81 
82  mmf->stereo = s->streams[0]->codec->channels > 1;
83  if (mmf->stereo &&
85  av_log(s, AV_LOG_ERROR, "Yamaha SMAF stereo is experimental, "
86  "add '-strict %d' if you want to use it.\n",
88  return AVERROR(EINVAL);
89  }
90 
91  ffio_wfourcc(pb, "MMMD");
92  avio_wb32(pb, 0);
93  pos = ff_start_tag(pb, "CNTI");
94  avio_w8(pb, 0); /* class */
95  avio_w8(pb, 1); /* type */
96  avio_w8(pb, 1); /* code type */
97  avio_w8(pb, 0); /* status */
98  avio_w8(pb, 0); /* counts */
99  end_tag_be(pb, pos);
100  pos = ff_start_tag(pb, "OPDA");
101  avio_write(pb, version, strlen(version)); /* metadata ("ST:songtitle,VN:version,...") */
102  end_tag_be(pb, pos);
103 
104  avio_write(pb, "ATR\x00", 4);
105  avio_wb32(pb, 0);
106  mmf->atrpos = avio_tell(pb);
107  avio_w8(pb, 0); /* format type */
108  avio_w8(pb, 0); /* sequence type */
109  avio_w8(pb, (mmf->stereo << 7) | (1 << 4) | rate); /* (channel << 7) | (format << 4) | rate */
110  avio_w8(pb, 0); /* wave base bit */
111  avio_w8(pb, 2); /* time base d */
112  avio_w8(pb, 2); /* time base g */
113 
114  ffio_wfourcc(pb, "Atsq");
115  avio_wb32(pb, 16);
116  mmf->atsqpos = avio_tell(pb);
117  /* Will be filled on close */
118  avio_write(pb, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16);
119 
120  mmf->awapos = ff_start_tag(pb, "Awa\x01");
121 
122  avpriv_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);
123 
124  avio_flush(pb);
125 
126  return 0;
127 }
128 
129 /* Write a variable-length symbol */
130 static void put_varlength(AVIOContext *pb, int val)
131 {
132  if(val < 128)
133  avio_w8(pb, val);
134  else {
135  val -= 128;
136  avio_w8(pb, 0x80 | val >> 7);
137  avio_w8(pb, 0x7f & val);
138  }
139 }
140 
141 static int mmf_write_trailer(AVFormatContext *s)
142 {
143  AVIOContext *pb = s->pb;
144  MMFContext *mmf = s->priv_data;
145  int64_t pos, size;
146  int gatetime;
147 
148  if (s->pb->seekable) {
149  /* Fill in length fields */
150  end_tag_be(pb, mmf->awapos);
151  end_tag_be(pb, mmf->atrpos);
152  end_tag_be(pb, 8);
153 
154  pos = avio_tell(pb);
155  size = pos - mmf->awapos;
156 
157  /* Fill Atsq chunk */
158  avio_seek(pb, mmf->atsqpos, SEEK_SET);
159 
160  /* "play wav" */
161  avio_w8(pb, 0); /* start time */
162  avio_w8(pb, (mmf->stereo << 6) | 1); /* (channel << 6) | wavenum */
163  gatetime = size * 500 / s->streams[0]->codec->sample_rate;
164  put_varlength(pb, gatetime); /* duration */
165 
166  /* "nop" */
167  put_varlength(pb, gatetime); /* start time */
168  avio_write(pb, "\xff\x00", 2); /* nop */
169 
170  /* "end of sequence" */
171  avio_write(pb, "\x00\x00\x00\x00", 4);
172 
173  avio_seek(pb, pos, SEEK_SET);
174 
175  avio_flush(pb);
176  }
177  return 0;
178 }
179 #endif /* CONFIG_MMF_MUXER */
180 
181 static int mmf_probe(AVProbeData *p)
182 {
183  /* check file header */
184  if (p->buf[0] == 'M' && p->buf[1] == 'M' &&
185  p->buf[2] == 'M' && p->buf[3] == 'D' &&
186  p->buf[8] == 'C' && p->buf[9] == 'N' &&
187  p->buf[10] == 'T' && p->buf[11] == 'I')
188  return AVPROBE_SCORE_MAX;
189  else
190  return 0;
191 }
192 
193 /* mmf input */
195 {
196  MMFContext *mmf = s->priv_data;
197  unsigned int tag;
198  AVIOContext *pb = s->pb;
199  AVStream *st;
200  int64_t size;
201  int rate, params;
202 
203  tag = avio_rl32(pb);
204  if (tag != MKTAG('M', 'M', 'M', 'D'))
205  return AVERROR_INVALIDDATA;
206  avio_skip(pb, 4); /* file_size */
207 
208  /* Skip some unused chunks that may or may not be present */
209  for(;; avio_skip(pb, size)) {
210  tag = avio_rl32(pb);
211  size = avio_rb32(pb);
212  if(tag == MKTAG('C','N','T','I')) continue;
213  if(tag == MKTAG('O','P','D','A')) continue;
214  break;
215  }
216 
217  /* Tag = "ATRx", where "x" = track number */
218  if ((tag & 0xffffff) == MKTAG('M', 'T', 'R', 0)) {
219  av_log(s, AV_LOG_ERROR, "MIDI like format found, unsupported\n");
220  return AVERROR_PATCHWELCOME;
221  }
222  if ((tag & 0xffffff) != MKTAG('A', 'T', 'R', 0)) {
223  av_log(s, AV_LOG_ERROR, "Unsupported SMAF chunk %08x\n", tag);
224  return AVERROR_PATCHWELCOME;
225  }
226 
227  avio_r8(pb); /* format type */
228  avio_r8(pb); /* sequence type */
229  params = avio_r8(pb); /* (channel << 7) | (format << 4) | rate */
230  rate = mmf_rate(params & 0x0f);
231  if(rate < 0) {
232  av_log(s, AV_LOG_ERROR, "Invalid sample rate\n");
233  return AVERROR_INVALIDDATA;
234  }
235  avio_r8(pb); /* wave base bit */
236  avio_r8(pb); /* time base d */
237  avio_r8(pb); /* time base g */
238 
239  /* Skip some unused chunks that may or may not be present */
240  for(;; avio_skip(pb, size)) {
241  tag = avio_rl32(pb);
242  size = avio_rb32(pb);
243  if(tag == MKTAG('A','t','s','q')) continue;
244  if(tag == MKTAG('A','s','p','I')) continue;
245  break;
246  }
247 
248  /* Make sure it's followed by an Awa chunk, aka wave data */
249  if ((tag & 0xffffff) != MKTAG('A', 'w', 'a', 0)) {
250  av_log(s, AV_LOG_ERROR, "Unexpected SMAF chunk %08x\n", tag);
251  return AVERROR_INVALIDDATA;
252  }
253  mmf->data_end = avio_tell(pb) + size;
254 
255  st = avformat_new_stream(s, NULL);
256  if (!st)
257  return AVERROR(ENOMEM);
258 
261  st->codec->sample_rate = rate;
262  st->codec->channels = (params >> 7) + 1;
264  st->codec->bits_per_coded_sample = 4;
266 
267  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
268 
269  return 0;
270 }
271 
272 #define MAX_SIZE 4096
273 
275  AVPacket *pkt)
276 {
277  MMFContext *mmf = s->priv_data;
278  int64_t left, size;
279  int ret;
280 
281  left = mmf->data_end - avio_tell(s->pb);
282  size = FFMIN(left, MAX_SIZE);
283  if (url_feof(s->pb) || size <= 0)
284  return AVERROR_EOF;
285 
286  ret = av_get_packet(s->pb, pkt, size);
287  if (ret < 0)
288  return ret;
289 
290  pkt->stream_index = 0;
291 
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,
317  .write_trailer = mmf_write_trailer,
318 };
319 #endif