FFmpeg: libavformat/concatdec.c Source File

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libavformat

concatdec.c

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1 /*

3 *

4 * This file is part of FFmpeg.

5 *

6 * FFmpeg is free software; you can redistribute it and/or

7 * modify it under the terms of the GNU Lesser General Public License

8 * as published by the Free Software Foundation; either

9 * version 2.1 of the License, or (at your option) any later version.

10 *

11 * FFmpeg is distributed in the hope that it will be useful,

12 * but WITHOUT ANY WARRANTY; without even the implied warranty of

13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

14 * GNU Lesser General Public License for more details.

15 *

16 * You should have received a copy of the GNU Lesser General Public License

17 * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,

18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

19 */

21 #include "libavutil/avstring.h"

22 #include "libavutil/opt.h"

23 #include "libavutil/parseutils.h"

24 #include "avformat.h"

25 #include "internal.h"

26 #include "url.h"

28 typedef struct {

29 char *url;

30 int64_t start_time;

31 int64_t duration;

32 } ConcatFile;

34 typedef struct {

35 AVClass *class;

36 ConcatFile *files;

37 ConcatFile *cur_file;

38 unsigned nb_files;

39 AVFormatContext *avf;

40 int safe;

41 int seekable;

42 } ConcatContext;

44 static int concat_probe(AVProbeData *probe)

45 {

46 return memcmp(probe->buf, "ffconcat version 1.0", 20) ?

47 0 : AVPROBE_SCORE_MAX;

48 }

50 static char *get_keyword(uint8_t **cursor)

51 {

52 char *ret = *cursor += strspn(*cursor, SPACE_CHARS);

53 *cursor += strcspn(*cursor, SPACE_CHARS);

54 if (**cursor) {

55 *((*cursor)++) = 0;

56 *cursor += strspn(*cursor, SPACE_CHARS);

57 }

58 return ret;

59 }

61 static int safe_filename(const char *f)

62 {

63 const char *start = f;

65 for (; *f; f++) {

66 /* A-Za-z0-9_- */

67 if (!((unsigned)((*f | 32) - 'a') < 26 ||

68 (unsigned)(*f - '0') < 10 || *f == '_' || *f == '-')) {

69 if (f == start)

70 return 0;

71 else if (*f == '/')

72 start = f + 1;

73 else if (*f != '.')

74 return 0;

75 }

76 }

77 return 1;

78 }

80 #define FAIL(retcode) do { ret = (retcode); goto fail; } while(0)

82 static int add_file(AVFormatContext *avf, char *filename, ConcatFile **rfile,

83 unsigned *nb_files_alloc)

84 {

85 ConcatContext *cat = avf->priv_data;

86 ConcatFile *file;

87 char *url = NULL;

88 size_t url_len;

89 int ret;

91 if (cat->safe > 0 && !safe_filename(filename)) {

92 av_log(avf, AV_LOG_ERROR, "Unsafe file name '%s'\n", filename);

93 FAIL(AVERROR(EPERM));

94 }

95 url_len = strlen(avf->filename) + strlen(filename) + 16;

96 if (!(url = av_malloc(url_len)))

97 FAIL(AVERROR(ENOMEM));

98 ff_make_absolute_url(url, url_len, avf->filename, filename);

99 av_freep(&filename);

100

101 if (cat->nb_files >= *nb_files_alloc) {

102 size_t n = FFMAX(*nb_files_alloc * 2, 16);

103 ConcatFile *new_files;

104 if (n <= cat->nb_files || n > SIZE_MAX / sizeof(*cat->files) ||

105 !(new_files = av_realloc(cat->files, n * sizeof(*cat->files))))

106 FAIL(AVERROR(ENOMEM));

107 cat->files = new_files;

108 *nb_files_alloc = n;

109 }

110

111 file = &cat->files[cat->nb_files++];

112 memset(file, 0, sizeof(*file));

113 *rfile = file;

114

115 file->url = url;

116 file->start_time = AV_NOPTS_VALUE;

117 file->duration = AV_NOPTS_VALUE;

118

119 return 0;

120

121 fail:

122 av_free(url);

123 av_free(filename);

124 return ret;

125 }

126

127 static int open_file(AVFormatContext *avf, unsigned fileno)

128 {

129 ConcatContext *cat = avf->priv_data;

130 ConcatFile *file = &cat->files[fileno];

131 int ret;

132

133 if (cat->avf)

134 avformat_close_input(&cat->avf);

135 if ((ret = avformat_open_input(&cat->avf, file->url, NULL, NULL)) < 0 ||

136 (ret = avformat_find_stream_info(cat->avf, NULL)) < 0) {

137 av_log(avf, AV_LOG_ERROR, "Impossible to open '%s'\n", file->url);

138 return ret;

139 }

140 cat->cur_file = file;

141 if (file->start_time == AV_NOPTS_VALUE)

142 file->start_time = !fileno ? 0 :

143 cat->files[fileno - 1].start_time +

144 cat->files[fileno - 1].duration;

145 return 0;

146 }

147

148 static int concat_read_close(AVFormatContext *avf)

149 {

150 ConcatContext *cat = avf->priv_data;

151 unsigned i;

152

153 if (cat->avf)

154 avformat_close_input(&cat->avf);

155 for (i = 0; i < cat->nb_files; i++)

156 av_freep(&cat->files[i].url);

157 av_freep(&cat->files);

158 return 0;

159 }

160

161 static int concat_read_header(AVFormatContext *avf)

162 {

163 ConcatContext *cat = avf->priv_data;

164 uint8_t buf[4096];

165 uint8_t *cursor, *keyword;

166 int ret, line = 0, i;

167 unsigned nb_files_alloc = 0;

168 ConcatFile *file = NULL;

169 AVStream *st, *source_st;

170 int64_t time = 0;

171

172 while (1) {

173 if ((ret = ff_get_line(avf->pb, buf, sizeof(buf))) <= 0)

174 break;

175 line++;

176 cursor = buf;

177 keyword = get_keyword(&cursor);

178 if (!*keyword || *keyword == '#')

179 continue;

180

181 if (!strcmp(keyword, "file")) {

182 char *filename = av_get_token((const char **)&cursor, SPACE_CHARS);

183 if (!filename) {

184 av_log(avf, AV_LOG_ERROR, "Line %d: filename required\n", line);

185 FAIL(AVERROR_INVALIDDATA);

186 }

187 if ((ret = add_file(avf, filename, &file, &nb_files_alloc)) < 0)

188 FAIL(ret);

189 } else if (!strcmp(keyword, "duration")) {

190 char *dur_str = get_keyword(&cursor);

191 int64_t dur;

192 if (!file) {

193 av_log(avf, AV_LOG_ERROR, "Line %d: duration without file\n",

194 line);

195 FAIL(AVERROR_INVALIDDATA);

196 }

197 if ((ret = av_parse_time(&dur, dur_str, 1)) < 0) {

198 av_log(avf, AV_LOG_ERROR, "Line %d: invalid duration '%s'\n",

199 line, dur_str);

200 FAIL(ret);

201 }

202 file->duration = dur;

203 } else if (!strcmp(keyword, "ffconcat")) {

204 char *ver_kw = get_keyword(&cursor);

205 char *ver_val = get_keyword(&cursor);

206 if (strcmp(ver_kw, "version") || strcmp(ver_val, "1.0")) {

207 av_log(avf, AV_LOG_ERROR, "Line %d: invalid version\n", line);

208 FAIL(AVERROR_INVALIDDATA);

209 }

210 if (cat->safe < 0)

211 cat->safe = 1;

212 } else {

213 av_log(avf, AV_LOG_ERROR, "Line %d: unknown keyword '%s'\n",

214 line, keyword);

215 FAIL(AVERROR_INVALIDDATA);

216 }

217 }

218 if (ret < 0)

219 FAIL(ret);

220 if (!cat->nb_files)

221 FAIL(AVERROR_INVALIDDATA);

222

223 for (i = 0; i < cat->nb_files; i++) {

224 if (cat->files[i].start_time == AV_NOPTS_VALUE)

225 cat->files[i].start_time = time;

226 else

227 time = cat->files[i].start_time;

228 if (cat->files[i].duration == AV_NOPTS_VALUE)

229 break;

230 time += cat->files[i].duration;

231 }

232 if (i == cat->nb_files) {

233 avf->duration = time;

234 cat->seekable = 1;

235 }

236

237 if ((ret = open_file(avf, 0)) < 0)

238 FAIL(ret);

239 for (i = 0; i < cat->avf->nb_streams; i++) {

240 if (!(st = avformat_new_stream(avf, NULL)))

241 FAIL(AVERROR(ENOMEM));

242 source_st = cat->avf->streams[i];

243 if ((ret = avcodec_copy_context(st->codec, source_st->codec)) < 0)

244 FAIL(ret);

245 st->r_frame_rate = source_st->r_frame_rate;

246 st->avg_frame_rate = source_st->avg_frame_rate;

247 st->time_base = source_st->time_base;

248 st->sample_aspect_ratio = source_st->sample_aspect_ratio;

249 }

250

251 return 0;

252

253 fail:

254 concat_read_close(avf);

255 return ret;

256 }

257

258 static int open_next_file(AVFormatContext *avf)

259 {

260 ConcatContext *cat = avf->priv_data;

261 unsigned fileno = cat->cur_file - cat->files;

262

263 if (cat->cur_file->duration == AV_NOPTS_VALUE)

264 cat->cur_file->duration = cat->avf->duration;

265

266 if (++fileno >= cat->nb_files)

267 return AVERROR_EOF;

268 return open_file(avf, fileno);

269 }

270

271 static int concat_read_packet(AVFormatContext *avf, AVPacket *pkt)

272 {

273 ConcatContext *cat = avf->priv_data;

274 int ret;

275 int64_t delta;

276

277 while (1) {

278 if ((ret = av_read_frame(cat->avf, pkt)) != AVERROR_EOF ||

279 (ret = open_next_file(avf)) < 0)

280 break;

281 }

282 delta = av_rescale_q(cat->cur_file->start_time - cat->avf->start_time,

283 AV_TIME_BASE_Q,

284 cat->avf->streams[pkt->stream_index]->time_base);

285 if (pkt->pts != AV_NOPTS_VALUE)

286 pkt->pts += delta;

287 if (pkt->dts != AV_NOPTS_VALUE)

288 pkt->dts += delta;

289 return ret;

290 }

291

292 static void rescale_interval(AVRational tb_in, AVRational tb_out,

293 int64_t *min_ts, int64_t *ts, int64_t *max_ts)

294 {

295 *ts = av_rescale_q (* ts, tb_in, tb_out);

296 *min_ts = av_rescale_q_rnd(*min_ts, tb_in, tb_out,

297 AV_ROUND_UP | AV_ROUND_PASS_MINMAX);

298 *max_ts = av_rescale_q_rnd(*max_ts, tb_in, tb_out,

299 AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);

300 }

301

302 static int try_seek(AVFormatContext *avf, int stream,

303 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)

304 {

305 ConcatContext *cat = avf->priv_data;

306 int64_t t0 = cat->cur_file->start_time - cat->avf->start_time;

307

308 ts -= t0;

309 min_ts = min_ts == INT64_MIN ? INT64_MIN : min_ts - t0;

310 max_ts = max_ts == INT64_MAX ? INT64_MAX : max_ts - t0;

311 if (stream >= 0) {

312 if (stream >= cat->avf->nb_streams)

313 return AVERROR(EIO);

314 rescale_interval(AV_TIME_BASE_Q, cat->avf->streams[stream]->time_base,

315 &min_ts, &ts, &max_ts);

316 }

317 return avformat_seek_file(cat->avf, stream, min_ts, ts, max_ts, flags);

318 }

319

320 static int real_seek(AVFormatContext *avf, int stream,

321 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)

322 {

323 ConcatContext *cat = avf->priv_data;

324 int ret, left, right;

325

326 if (stream >= 0) {

327 if (stream >= avf->nb_streams)

328 return AVERROR(EINVAL);

329 rescale_interval(avf->streams[stream]->time_base, AV_TIME_BASE_Q,

330 &min_ts, &ts, &max_ts);

331 }

332

333 left = 0;

334 right = cat->nb_files;

335 while (right - left > 1) {

336 int mid = (left + right) / 2;

337 if (ts < cat->files[mid].start_time)

338 right = mid;

339 else

340 left = mid;

341 }

342

343 if ((ret = open_file(avf, left)) < 0)

344 return ret;

345

346 ret = try_seek(avf, stream, min_ts, ts, max_ts, flags);

347 if (ret < 0 &&

348 left < cat->nb_files - 1 &&

349 cat->files[left + 1].start_time < max_ts) {

350 if ((ret = open_file(avf, left + 1)) < 0)

351 return ret;

352 ret = try_seek(avf, stream, min_ts, ts, max_ts, flags);

353 }

354 return ret;

355 }

356

357 static int concat_seek(AVFormatContext *avf, int stream,

358 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)

359 {

360 ConcatContext *cat = avf->priv_data;

361 ConcatFile *cur_file_saved = cat->cur_file;

362 AVFormatContext *cur_avf_saved = cat->avf;

363 int ret;

364

365 if (!cat->seekable)

366 return AVERROR(ESPIPE); /* XXX: can we use it? */

367 if (flags & (AVSEEK_FLAG_BYTE | AVSEEK_FLAG_FRAME))

368 return AVERROR(ENOSYS);

369 cat->avf = NULL;

370 if ((ret = real_seek(avf, stream, min_ts, ts, max_ts, flags)) < 0) {

371 if (cat->avf)

372 avformat_close_input(&cat->avf);

373 cat->avf = cur_avf_saved;

374 cat->cur_file = cur_file_saved;

375 } else {

376 avformat_close_input(&cur_avf_saved);

377 }

378 return ret;

379 }

380

381 #define OFFSET(x) offsetof(ConcatContext, x)

382 #define DEC AV_OPT_FLAG_DECODING_PARAM

383

384 static const AVOption options[] = {

385 { "safe", "enable safe mode",

386 OFFSET(safe), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, DEC },

387 { NULL }

388 };

389

390 static const AVClass concat_class = {

391 .class_name = "concat demuxer",

392 .item_name = av_default_item_name,

393 .option = options,

394 .version = LIBAVUTIL_VERSION_INT,

395 };

396

397

398 AVInputFormat ff_concat_demuxer = {

399 .name = "concat",

400 .long_name = NULL_IF_CONFIG_SMALL("Virtual concatenation script"),

401 .priv_data_size = sizeof(ConcatContext),

402 .read_probe = concat_probe,

403 .read_header = concat_read_header,

404 .read_packet = concat_read_packet,

405 .read_close = concat_read_close,

406 .read_seek2 = concat_seek,

407 .priv_class = &concat_class,

408 };

Generated on Sat Jan 25 2014 19:52:02 for FFmpeg by doxygen 1.8.2