FFmpeg: libavformat/nuv.c Source File

FFmpeg

[フレーム]

libavformat

nuv.c

Go to the documentation of this file.

1 /*

2 * NuppelVideo demuxer.

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 */

22 #include "libavutil/channel_layout.h"

23 #include "libavutil/intreadwrite.h"

24 #include "libavutil/intfloat.h"

25 #include "avformat.h"

26 #include "internal.h"

27 #include "riff.h"

29 static const AVCodecTag nuv_audio_tags[] = {

30 { AV_CODEC_ID_PCM_S16LE, MKTAG('R', 'A', 'W', 'A') },

31 { AV_CODEC_ID_MP3, MKTAG('L', 'A', 'M', 'E') },

32 { AV_CODEC_ID_NONE, 0 },

33 };

35 typedef struct {

36 int v_id;

37 int a_id;

38 int rtjpg_video;

39 } NUVContext;

41 typedef enum {

42 NUV_VIDEO = 'V',

43 NUV_EXTRADATA = 'D',

44 NUV_AUDIO = 'A',

45 NUV_SEEKP = 'R',

46 NUV_MYTHEXT = 'X'

47 } nuv_frametype;

49 static int nuv_probe(AVProbeData *p)

50 {

51 if (!memcmp(p->buf, "NuppelVideo", 12))

52 return AVPROBE_SCORE_MAX;

53 if (!memcmp(p->buf, "MythTVVideo", 12))

54 return AVPROBE_SCORE_MAX;

55 return 0;

56 }

58 /// little macro to sanitize packet size

59 #define PKTSIZE(s) (s & 0xffffff)

61 /**

62 * @brief read until we found all data needed for decoding

63 * @param vst video stream of which to change parameters

64 * @param ast video stream of which to change parameters

65 * @param myth set if this is a MythTVVideo format file

66 * @return 0 or AVERROR code

67 */

68 static int get_codec_data(AVIOContext *pb, AVStream *vst,

69 AVStream *ast, int myth)

70 {

71 nuv_frametype frametype;

73 if (!vst && !myth)

74 return 1; // no codec data needed

75 while (!url_feof(pb)) {

76 int size, subtype;

78 frametype = avio_r8(pb);

79 switch (frametype) {

80 case NUV_EXTRADATA:

81 subtype = avio_r8(pb);

82 avio_skip(pb, 6);

83 size = PKTSIZE(avio_rl32(pb));

84 if (vst && subtype == 'R') {

85 if (vst->codec->extradata) {

86 av_freep(&vst->codec->extradata);

87 vst->codec->extradata_size = 0;

88 }

89 vst->codec->extradata = av_malloc(size);

90 if (!vst->codec->extradata)

91 return AVERROR(ENOMEM);

92 vst->codec->extradata_size = size;

93 avio_read(pb, vst->codec->extradata, size);

94 size = 0;

95 if (!myth)

96 return 0;

97 }

98 break;

99 case NUV_MYTHEXT:

100 avio_skip(pb, 7);

101 size = PKTSIZE(avio_rl32(pb));

102 if (size != 128 * 4)

103 break;

104 avio_rl32(pb); // version

105 if (vst) {

106 vst->codec->codec_tag = avio_rl32(pb);

107 vst->codec->codec_id =

108 ff_codec_get_id(ff_codec_bmp_tags, vst->codec->codec_tag);

109 if (vst->codec->codec_tag == MKTAG('R', 'J', 'P', 'G'))

110 vst->codec->codec_id = AV_CODEC_ID_NUV;

111 } else

112 avio_skip(pb, 4);

113

114 if (ast) {

115 int id;

116

117 ast->codec->codec_tag = avio_rl32(pb);

118 ast->codec->sample_rate = avio_rl32(pb);

119 ast->codec->bits_per_coded_sample = avio_rl32(pb);

120 ast->codec->channels = avio_rl32(pb);

121 ast->codec->channel_layout = 0;

122

123 id = ff_wav_codec_get_id(ast->codec->codec_tag,

124 ast->codec->bits_per_coded_sample);

125 if (id == AV_CODEC_ID_NONE) {

126 id = ff_codec_get_id(nuv_audio_tags, ast->codec->codec_tag);

127 if (id == AV_CODEC_ID_PCM_S16LE)

128 id = ff_get_pcm_codec_id(ast->codec->bits_per_coded_sample,

129 0, 0, ~1);

130 }

131 ast->codec->codec_id = id;

132

133 ast->need_parsing = AVSTREAM_PARSE_FULL;

134 } else

135 avio_skip(pb, 4 * 4);

136

137 size -= 6 * 4;

138 avio_skip(pb, size);

139 return 0;

140 case NUV_SEEKP:

141 size = 11;

142 break;

143 default:

144 avio_skip(pb, 7);

145 size = PKTSIZE(avio_rl32(pb));

146 break;

147 }

148 avio_skip(pb, size);

149 }

150

151 return 0;

152 }

153

154 static int nuv_header(AVFormatContext *s)

155 {

156 NUVContext *ctx = s->priv_data;

157 AVIOContext *pb = s->pb;

158 char id_string[12];

159 double aspect, fps;

160 int is_mythtv, width, height, v_packs, a_packs, ret;

161 AVStream *vst = NULL, *ast = NULL;

162

163 avio_read(pb, id_string, 12);

164 is_mythtv = !memcmp(id_string, "MythTVVideo", 12);

165 avio_skip(pb, 5); // version string

166 avio_skip(pb, 3); // padding

167 width = avio_rl32(pb);

168 height = avio_rl32(pb);

169 avio_rl32(pb); // unused, "desiredwidth"

170 avio_rl32(pb); // unused, "desiredheight"

171 avio_r8(pb); // 'P' == progressive, 'I' == interlaced

172 avio_skip(pb, 3); // padding

173 aspect = av_int2double(avio_rl64(pb));

174 if (aspect > 0.9999 && aspect < 1.0001)

175 aspect = 4.0 / 3.0;

176 fps = av_int2double(avio_rl64(pb));

177

178 // number of packets per stream type, -1 means unknown, e.g. streaming

179 v_packs = avio_rl32(pb);

180 a_packs = avio_rl32(pb);

181 avio_rl32(pb); // text

182

183 avio_rl32(pb); // keyframe distance (?)

184

185 if (v_packs) {

186 vst = avformat_new_stream(s, NULL);

187 if (!vst)

188 return AVERROR(ENOMEM);

189 ctx->v_id = vst->index;

190

191 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;

192 vst->codec->codec_id = AV_CODEC_ID_NUV;

193 vst->codec->width = width;

194 vst->codec->height = height;

195 vst->codec->bits_per_coded_sample = 10;

196 vst->sample_aspect_ratio = av_d2q(aspect * height / width,

197 10000);

198 #if FF_API_R_FRAME_RATE

199 vst->r_frame_rate =

200 #endif

201 vst->avg_frame_rate = av_d2q(fps, 60000);

202 avpriv_set_pts_info(vst, 32, 1, 1000);

203 } else

204 ctx->v_id = -1;

205

206 if (a_packs) {

207 ast = avformat_new_stream(s, NULL);

208 if (!ast)

209 return AVERROR(ENOMEM);

210 ctx->a_id = ast->index;

211

212 ast->codec->codec_type = AVMEDIA_TYPE_AUDIO;

213 ast->codec->codec_id = AV_CODEC_ID_PCM_S16LE;

214 ast->codec->channels = 2;

215 ast->codec->channel_layout = AV_CH_LAYOUT_STEREO;

216 ast->codec->sample_rate = 44100;

217 ast->codec->bit_rate = 2 * 2 * 44100 * 8;

218 ast->codec->block_align = 2 * 2;

219 ast->codec->bits_per_coded_sample = 16;

220 avpriv_set_pts_info(ast, 32, 1, 1000);

221 } else

222 ctx->a_id = -1;

223

224 if ((ret = get_codec_data(pb, vst, ast, is_mythtv)) < 0)

225 return ret;

226

227 ctx->rtjpg_video = vst && vst->codec->codec_id == AV_CODEC_ID_NUV;

228

229 return 0;

230 }

231

232 #define HDRSIZE 12

233

234 static int nuv_packet(AVFormatContext *s, AVPacket *pkt)

235 {

236 NUVContext *ctx = s->priv_data;

237 AVIOContext *pb = s->pb;

238 uint8_t hdr[HDRSIZE];

239 nuv_frametype frametype;

240 int ret, size;

241

242 while (!url_feof(pb)) {

243 int copyhdrsize = ctx->rtjpg_video ? HDRSIZE : 0;

244 uint64_t pos = avio_tell(pb);

245

246 ret = avio_read(pb, hdr, HDRSIZE);

247 if (ret < HDRSIZE)

248 return ret < 0 ? ret : AVERROR(EIO);

249

250 frametype = hdr[0];

251 size = PKTSIZE(AV_RL32(&hdr[8]));

252

253 switch (frametype) {

254 case NUV_EXTRADATA:

255 if (!ctx->rtjpg_video) {

256 avio_skip(pb, size);

257 break;

258 }

259 case NUV_VIDEO:

260 if (ctx->v_id < 0) {

261 av_log(s, AV_LOG_ERROR, "Video packet in file without video stream!\n");

262 avio_skip(pb, size);

263 break;

264 }

265 ret = av_new_packet(pkt, copyhdrsize + size);

266 if (ret < 0)

267 return ret;

268

269 pkt->pos = pos;

270 pkt->flags |= hdr[2] == 0 ? AV_PKT_FLAG_KEY : 0;

271 pkt->pts = AV_RL32(&hdr[4]);

272 pkt->stream_index = ctx->v_id;

273 memcpy(pkt->data, hdr, copyhdrsize);

274 ret = avio_read(pb, pkt->data + copyhdrsize, size);

275 if (ret < 0) {

276 av_free_packet(pkt);

277 return ret;

278 }

279 if (ret < size)

280 av_shrink_packet(pkt, copyhdrsize + ret);

281 return 0;

282 case NUV_AUDIO:

283 if (ctx->a_id < 0) {

284 av_log(s, AV_LOG_ERROR, "Audio packet in file without audio stream!\n");

285 avio_skip(pb, size);

286 break;

287 }

288 ret = av_get_packet(pb, pkt, size);

289 pkt->flags |= AV_PKT_FLAG_KEY;

290 pkt->pos = pos;

291 pkt->pts = AV_RL32(&hdr[4]);

292 pkt->stream_index = ctx->a_id;

293 if (ret < 0)

294 return ret;

295 return 0;

296 case NUV_SEEKP:

297 // contains no data, size value is invalid

298 break;

299 default:

300 avio_skip(pb, size);

301 break;

302 }

303 }

304

305 return AVERROR(EIO);

306 }

307

308 /**

309 * \brief looks for the string RTjjjjjjjjjj in the stream too resync reading

310 * \return 1 if the syncword is found 0 otherwise.

311 */

312 static int nuv_resync(AVFormatContext *s, int64_t pos_limit) {

313 AVIOContext *pb = s->pb;

314 uint32_t tag = 0;

315 while(!url_feof(pb) && avio_tell(pb) < pos_limit) {

316 tag = (tag << 8) | avio_r8(pb);

317 if (tag == MKBETAG('R','T','j','j') &&

318 (tag = avio_rb32(pb)) == MKBETAG('j','j','j','j') &&

319 (tag = avio_rb32(pb)) == MKBETAG('j','j','j','j'))

320 return 1;

321 }

322 return 0;

323 }

324

325 /**

326 * \brief attempts to read a timestamp from stream at the given stream position

327 * \return timestamp if successful and AV_NOPTS_VALUE if failure

328 */

329 static int64_t nuv_read_dts(AVFormatContext *s, int stream_index,

330 int64_t *ppos, int64_t pos_limit)

331 {

332 NUVContext *ctx = s->priv_data;

333 AVIOContext *pb = s->pb;

334 uint8_t hdr[HDRSIZE];

335 nuv_frametype frametype;

336 int size, key, idx;

337 int64_t pos, dts;

338

339 if (avio_seek(pb, *ppos, SEEK_SET) < 0)

340 return AV_NOPTS_VALUE;

341

342 if (!nuv_resync(s, pos_limit))

343 return AV_NOPTS_VALUE;

344

345 while (!url_feof(pb) && avio_tell(pb) < pos_limit) {

346 if (avio_read(pb, hdr, HDRSIZE) < HDRSIZE)

347 return AV_NOPTS_VALUE;

348 frametype = hdr[0];

349 size = PKTSIZE(AV_RL32(&hdr[8]));

350 switch (frametype) {

351 case NUV_SEEKP:

352 break;

353 case NUV_AUDIO:

354 case NUV_VIDEO:

355 if (frametype == NUV_VIDEO) {

356 idx = ctx->v_id;

357 key = hdr[2] == 0;

358 } else {

359 idx = ctx->a_id;

360 key = 1;

361 }

362 if (stream_index == idx) {

363

364 pos = avio_tell(s->pb) - HDRSIZE;

365 dts = AV_RL32(&hdr[4]);

366

367 // TODO - add general support in av_gen_search, so it adds positions after reading timestamps

368 av_add_index_entry(s->streams[stream_index], pos, dts, size + HDRSIZE, 0,

369 key ? AVINDEX_KEYFRAME : 0);

370

371 *ppos = pos;

372 return dts;

373 }

374 default:

375 avio_skip(pb, size);

376 break;

377 }

378 }

379 return AV_NOPTS_VALUE;

380 }

381

382

383 AVInputFormat ff_nuv_demuxer = {

384 .name = "nuv",

385 .long_name = NULL_IF_CONFIG_SMALL("NuppelVideo"),

386 .priv_data_size = sizeof(NUVContext),

387 .read_probe = nuv_probe,

388 .read_header = nuv_header,

389 .read_packet = nuv_packet,

390 .read_timestamp = nuv_read_dts,

391 .flags = AVFMT_GENERIC_INDEX,

392 };

Generated on Wed Jul 10 2013 23:48:02 for FFmpeg by doxygen 1.8.2