FFmpeg: libavformat/rmenc.c Source File

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libavformat

rmenc.c

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1 /*

2 * "Real" compatible muxer.

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 #include "avformat.h"

22 #include "avio_internal.h"

23 #include "rm.h"

24 #include "libavutil/dict.h"

26 typedef struct {

27 int nb_packets;

28 int packet_total_size;

29 int packet_max_size;

30 /* codec related output */

31 int bit_rate;

32 float frame_rate;

33 int nb_frames; /* current frame number */

34 int total_frames; /* total number of frames */

35 int num;

36 AVCodecContext *enc;

37 } StreamInfo;

39 typedef struct {

40 StreamInfo streams[2];

41 StreamInfo *audio_stream, *video_stream;

42 int data_pos; /* position of the data after the header */

43 } RMMuxContext;

45 /* in ms */

46 #define BUFFER_DURATION 0

49 static void put_str(AVIOContext *s, const char *tag)

50 {

51 avio_wb16(s,strlen(tag));

52 while (*tag) {

53 avio_w8(s, *tag++);

54 }

55 }

57 static void put_str8(AVIOContext *s, const char *tag)

58 {

59 avio_w8(s, strlen(tag));

60 while (*tag) {

61 avio_w8(s, *tag++);

62 }

63 }

65 static int rv10_write_header(AVFormatContext *ctx,

66 int data_size, int index_pos)

67 {

68 RMMuxContext *rm = ctx->priv_data;

69 AVIOContext *s = ctx->pb;

70 StreamInfo *stream;

71 unsigned char *data_offset_ptr, *start_ptr;

72 const char *desc, *mimetype;

73 int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;

74 int bit_rate, v, duration, flags, data_pos;

75 AVDictionaryEntry *tag;

77 start_ptr = s->buf_ptr;

79 ffio_wfourcc(s, ".RMF");

80 avio_wb32(s,18); /* header size */

81 avio_wb16(s,0);

82 avio_wb32(s,0);

83 avio_wb32(s,4 + ctx->nb_streams); /* num headers */

85 ffio_wfourcc(s,"PROP");

86 avio_wb32(s, 50);

87 avio_wb16(s, 0);

88 packet_max_size = 0;

89 packet_total_size = 0;

90 nb_packets = 0;

91 bit_rate = 0;

92 duration = 0;

93 for(i=0;i<ctx->nb_streams;i++) {

94 StreamInfo *stream = &rm->streams[i];

95 bit_rate += stream->bit_rate;

96 if (stream->packet_max_size > packet_max_size)

97 packet_max_size = stream->packet_max_size;

98 nb_packets += stream->nb_packets;

99 packet_total_size += stream->packet_total_size;

100 /* select maximum duration */

101 v = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate);

102 if (v > duration)

103 duration = v;

104 }

105 avio_wb32(s, bit_rate); /* max bit rate */

106 avio_wb32(s, bit_rate); /* avg bit rate */

107 avio_wb32(s, packet_max_size); /* max packet size */

108 if (nb_packets > 0)

109 packet_avg_size = packet_total_size / nb_packets;

110 else

111 packet_avg_size = 0;

112 avio_wb32(s, packet_avg_size); /* avg packet size */

113 avio_wb32(s, nb_packets); /* num packets */

114 avio_wb32(s, duration); /* duration */

115 avio_wb32(s, BUFFER_DURATION); /* preroll */

116 avio_wb32(s, index_pos); /* index offset */

117 /* computation of data the data offset */

118 data_offset_ptr = s->buf_ptr;

119 avio_wb32(s, 0); /* data offset : will be patched after */

120 avio_wb16(s, ctx->nb_streams); /* num streams */

121 flags = 1 | 2; /* save allowed & perfect play */

122 if (!s->seekable)

123 flags |= 4; /* live broadcast */

124 avio_wb16(s, flags);

125

126 /* comments */

127

128 ffio_wfourcc(s,"CONT");

129 size = 4 * 2 + 10;

130 for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {

131 tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);

132 if(tag) size += strlen(tag->value);

133 }

134 avio_wb32(s,size);

135 avio_wb16(s,0);

136 for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {

137 tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);

138 put_str(s, tag ? tag->value : "");

139 }

140

141 for(i=0;i<ctx->nb_streams;i++) {

142 int codec_data_size;

143

144 stream = &rm->streams[i];

145

146 if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {

147 desc = "The Audio Stream";

148 mimetype = "audio/x-pn-realaudio";

149 codec_data_size = 73;

150 } else {

151 desc = "The Video Stream";

152 mimetype = "video/x-pn-realvideo";

153 codec_data_size = 34;

154 }

155

156 ffio_wfourcc(s,"MDPR");

157 size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;

158 avio_wb32(s, size);

159 avio_wb16(s, 0);

160

161 avio_wb16(s, i); /* stream number */

162 avio_wb32(s, stream->bit_rate); /* max bit rate */

163 avio_wb32(s, stream->bit_rate); /* avg bit rate */

164 avio_wb32(s, stream->packet_max_size); /* max packet size */

165 if (stream->nb_packets > 0)

166 packet_avg_size = stream->packet_total_size /

167 stream->nb_packets;

168 else

169 packet_avg_size = 0;

170 avio_wb32(s, packet_avg_size); /* avg packet size */

171 avio_wb32(s, 0); /* start time */

172 avio_wb32(s, BUFFER_DURATION); /* preroll */

173 /* duration */

174 if (!s->seekable || !stream->total_frames)

175 avio_wb32(s, (int)(3600 * 1000));

176 else

177 avio_wb32(s, (int)(stream->total_frames * 1000 / stream->frame_rate));

178 put_str8(s, desc);

179 put_str8(s, mimetype);

180 avio_wb32(s, codec_data_size);

181

182 if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {

183 int coded_frame_size, fscode, sample_rate;

184 sample_rate = stream->enc->sample_rate;

185 coded_frame_size = (stream->enc->bit_rate *

186 stream->enc->frame_size) / (8 * sample_rate);

187 /* audio codec info */

188 avio_write(s, ".ra", 3);

189 avio_w8(s, 0xfd);

190 avio_wb32(s, 0x00040000); /* version */

191 ffio_wfourcc(s, ".ra4");

192 avio_wb32(s, 0x01b53530); /* stream length */

193 avio_wb16(s, 4); /* unknown */

194 avio_wb32(s, 0x39); /* header size */

195

196 switch(sample_rate) {

197 case 48000:

198 case 24000:

199 case 12000:

200 fscode = 1;

201 break;

202 default:

203 case 44100:

204 case 22050:

205 case 11025:

206 fscode = 2;

207 break;

208 case 32000:

209 case 16000:

210 case 8000:

211 fscode = 3;

212 }

213 avio_wb16(s, fscode); /* codec additional info, for AC-3, seems

214 to be a frequency code */

215 /* special hack to compensate rounding errors... */

216 if (coded_frame_size == 557)

217 coded_frame_size--;

218 avio_wb32(s, coded_frame_size); /* frame length */

219 avio_wb32(s, 0x51540); /* unknown */

220 avio_wb32(s, stream->enc->bit_rate / 8 * 60); /* bytes per minute */

221 avio_wb32(s, stream->enc->bit_rate / 8 * 60); /* bytes per minute */

222 avio_wb16(s, 0x01);

223 /* frame length : seems to be very important */

224 avio_wb16(s, coded_frame_size);

225 avio_wb32(s, 0); /* unknown */

226 avio_wb16(s, stream->enc->sample_rate); /* sample rate */

227 avio_wb32(s, 0x10); /* unknown */

228 avio_wb16(s, stream->enc->channels);

229 put_str8(s, "Int0"); /* codec name */

230 if (stream->enc->codec_tag) {

231 avio_w8(s, 4); /* tag length */

232 avio_wl32(s, stream->enc->codec_tag);

233 } else {

234 av_log(ctx, AV_LOG_ERROR, "Invalid codec tag\n");

235 return -1;

236 }

237 avio_wb16(s, 0); /* title length */

238 avio_wb16(s, 0); /* author length */

239 avio_wb16(s, 0); /* copyright length */

240 avio_w8(s, 0); /* end of header */

241 } else {

242 /* video codec info */

243 avio_wb32(s,34); /* size */

244 ffio_wfourcc(s, "VIDO");

245 if(stream->enc->codec_id == AV_CODEC_ID_RV10)

246 ffio_wfourcc(s,"RV10");

247 else

248 ffio_wfourcc(s,"RV20");

249 avio_wb16(s, stream->enc->width);

250 avio_wb16(s, stream->enc->height);

251 avio_wb16(s, (int) stream->frame_rate); /* frames per seconds ? */

252 avio_wb32(s,0); /* unknown meaning */

253 avio_wb16(s, (int) stream->frame_rate); /* unknown meaning */

254 avio_wb32(s,0); /* unknown meaning */

255 avio_wb16(s, 8); /* unknown meaning */

256 /* Seems to be the codec version: only use basic H263. The next

257 versions seems to add a diffential DC coding as in

258 MPEG... nothing new under the sun */

259 if(stream->enc->codec_id == AV_CODEC_ID_RV10)

260 avio_wb32(s,0x10000000);

261 else

262 avio_wb32(s,0x20103001);

263 //avio_wb32(s,0x10003000);

264 }

265 }

266

267 /* patch data offset field */

268 data_pos = s->buf_ptr - start_ptr;

269 rm->data_pos = data_pos;

270 data_offset_ptr[0] = data_pos >> 24;

271 data_offset_ptr[1] = data_pos >> 16;

272 data_offset_ptr[2] = data_pos >> 8;

273 data_offset_ptr[3] = data_pos;

274

275 /* data stream */

276 ffio_wfourcc(s, "DATA");

277 avio_wb32(s,data_size + 10 + 8);

278 avio_wb16(s,0);

279

280 avio_wb32(s, nb_packets); /* number of packets */

281 avio_wb32(s,0); /* next data header */

282 return 0;

283 }

284

285 static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,

286 int length, int key_frame)

287 {

288 int timestamp;

289 AVIOContext *s = ctx->pb;

290

291 stream->nb_packets++;

292 stream->packet_total_size += length;

293 if (length > stream->packet_max_size)

294 stream->packet_max_size = length;

295

296 avio_wb16(s,0); /* version */

297 avio_wb16(s,length + 12);

298 avio_wb16(s, stream->num); /* stream number */

299 timestamp = (1000 * (float)stream->nb_frames) / stream->frame_rate;

300 avio_wb32(s, timestamp); /* timestamp */

301 avio_w8(s, 0); /* reserved */

302 avio_w8(s, key_frame ? 2 : 0); /* flags */

303 }

304

305 static int rm_write_header(AVFormatContext *s)

306 {

307 RMMuxContext *rm = s->priv_data;

308 StreamInfo *stream;

309 int n;

310 AVCodecContext *codec;

311

312 if (s->nb_streams > 2) {

313 av_log(s, AV_LOG_ERROR, "At most 2 streams are currently supported for muxing in RM\n");

314 return AVERROR_PATCHWELCOME;

315 }

316

317 for(n=0;n<s->nb_streams;n++) {

318 s->streams[n]->id = n;

319 codec = s->streams[n]->codec;

320 stream = &rm->streams[n];

321 memset(stream, 0, sizeof(StreamInfo));

322 stream->num = n;

323 stream->bit_rate = codec->bit_rate;

324 stream->enc = codec;

325

326 switch(codec->codec_type) {

327 case AVMEDIA_TYPE_AUDIO:

328 rm->audio_stream = stream;

329 stream->frame_rate = (float)codec->sample_rate / (float)codec->frame_size;

330 /* XXX: dummy values */

331 stream->packet_max_size = 1024;

332 stream->nb_packets = 0;

333 stream->total_frames = stream->nb_packets;

334 break;

335 case AVMEDIA_TYPE_VIDEO:

336 rm->video_stream = stream;

337 stream->frame_rate = (float)codec->time_base.den / (float)codec->time_base.num;

338 /* XXX: dummy values */

339 stream->packet_max_size = 4096;

340 stream->nb_packets = 0;

341 stream->total_frames = stream->nb_packets;

342 break;

343 default:

344 return -1;

345 }

346 }

347

348 if (rv10_write_header(s, 0, 0))

349 return AVERROR_INVALIDDATA;

350 avio_flush(s->pb);

351 return 0;

352 }

353

354 static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)

355 {

356 uint8_t *buf1;

357 RMMuxContext *rm = s->priv_data;

358 AVIOContext *pb = s->pb;

359 StreamInfo *stream = rm->audio_stream;

360 int i;

361

362 /* XXX: suppress this malloc */

363 buf1 = av_malloc(size * sizeof(uint8_t));

364

365 write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));

366

367 if (stream->enc->codec_id == AV_CODEC_ID_AC3) {

368 /* for AC-3, the words seem to be reversed */

369 for(i=0;i<size;i+=2) {

370 buf1[i] = buf[i+1];

371 buf1[i+1] = buf[i];

372 }

373 avio_write(pb, buf1, size);

374 } else {

375 avio_write(pb, buf, size);

376 }

377 stream->nb_frames++;

378 av_free(buf1);

379 return 0;

380 }

381

382 static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)

383 {

384 RMMuxContext *rm = s->priv_data;

385 AVIOContext *pb = s->pb;

386 StreamInfo *stream = rm->video_stream;

387 int key_frame = !!(flags & AV_PKT_FLAG_KEY);

388

389 /* XXX: this is incorrect: should be a parameter */

390

391 /* Well, I spent some time finding the meaning of these bits. I am

392 not sure I understood everything, but it works !! */

393 #if 1

394 write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);

395 /* bit 7: '1' if final packet of a frame converted in several packets */

396 avio_w8(pb, 0x81);

397 /* bit 7: '1' if I frame. bits 6..0 : sequence number in current

398 frame starting from 1 */

399 if (key_frame) {

400 avio_w8(pb, 0x81);

401 } else {

402 avio_w8(pb, 0x01);

403 }

404 if(size >= 0x4000){

405 avio_wb32(pb, size); /* total frame size */

406 avio_wb32(pb, size); /* offset from the start or the end */

407 }else{

408 avio_wb16(pb, 0x4000 | size); /* total frame size */

409 avio_wb16(pb, 0x4000 | size); /* offset from the start or the end */

410 }

411 #else

412 /* full frame */

413 write_packet_header(s, size + 6);

414 avio_w8(pb, 0xc0);

415 avio_wb16(pb, 0x4000 + size); /* total frame size */

416 avio_wb16(pb, 0x4000 + packet_number * 126); /* position in stream */

417 #endif

418 avio_w8(pb, stream->nb_frames & 0xff);

419

420 avio_write(pb, buf, size);

421

422 stream->nb_frames++;

423 return 0;

424 }

425

426 static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)

427 {

428 if (s->streams[pkt->stream_index]->codec->codec_type ==

429 AVMEDIA_TYPE_AUDIO)

430 return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);

431 else

432 return rm_write_video(s, pkt->data, pkt->size, pkt->flags);

433 }

434

435 static int rm_write_trailer(AVFormatContext *s)

436 {

437 RMMuxContext *rm = s->priv_data;

438 int data_size, index_pos, i;

439 AVIOContext *pb = s->pb;

440

441 if (s->pb->seekable) {

442 /* end of file: finish to write header */

443 index_pos = avio_tell(pb);

444 data_size = index_pos - rm->data_pos;

445

446 /* FIXME: write index */

447

448 /* undocumented end header */

449 avio_wb32(pb, 0);

450 avio_wb32(pb, 0);

451

452 avio_seek(pb, 0, SEEK_SET);

453 for(i=0;i<s->nb_streams;i++)

454 rm->streams[i].total_frames = rm->streams[i].nb_frames;

455 rv10_write_header(s, data_size, 0);

456 } else {

457 /* undocumented end header */

458 avio_wb32(pb, 0);

459 avio_wb32(pb, 0);

460 }

461

462 return 0;

463 }

464

465

466 AVOutputFormat ff_rm_muxer = {

467 .name = "rm",

468 .long_name = NULL_IF_CONFIG_SMALL("RealMedia"),

469 .mime_type = "application/vnd.rn-realmedia",

470 .extensions = "rm,ra",

471 .priv_data_size = sizeof(RMMuxContext),

472 .audio_codec = AV_CODEC_ID_AC3,

473 .video_codec = AV_CODEC_ID_RV10,

474 .write_header = rm_write_header,

475 .write_packet = rm_write_packet,

476 .write_trailer = rm_write_trailer,

477 .codec_tag = (const AVCodecTag* const []){ ff_rm_codec_tags, 0 },

478 };

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