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"

27 typedef struct {

28 char *url;

29 int64_t start_time;

30 int64_t duration;

31 } ConcatFile;

33 typedef struct {

34 AVClass *class;

35 ConcatFile *files;

36 ConcatFile *cur_file;

37 unsigned nb_files;

38 AVFormatContext *avf;

39 int safe;

40 } ConcatContext;

42 static int concat_probe(AVProbeData *probe)

43 {

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

45 0 : AVPROBE_SCORE_MAX;

46 }

48 static char *get_keyword(uint8_t **cursor)

49 {

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

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

52 if (**cursor) {

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

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

55 }

56 return ret;

57 }

59 static int safe_filename(const char *f)

60 {

61 const char *start = f;

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

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

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

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

67 if (f == start)

68 return 0;

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

70 start = f + 1;

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

72 return 0;

73 }

74 }

75 return 1;

76 }

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

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

81 unsigned *nb_files_alloc)

82 {

83 ConcatContext *cat = avf->priv_data;

84 ConcatFile *file;

85 char *url;

86 size_t url_len;

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

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

90 return AVERROR(EPERM);

91 }

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

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

94 return AVERROR(ENOMEM);

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

96 av_free(filename);

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

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

100 ConcatFile *new_files;

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

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

103 return AVERROR(ENOMEM);

104 cat->files = new_files;

105 *nb_files_alloc = n;

106 }

107

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

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

110 *rfile = file;

111

112 file->url = url;

113 file->start_time = AV_NOPTS_VALUE;

114 file->duration = AV_NOPTS_VALUE;

115

116 return 0;

117 }

118

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

120 {

121 ConcatContext *cat = avf->priv_data;

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

123 int ret;

124

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

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

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

128 return ret;

129 }

130 cat->cur_file = file;

131 if (file->start_time == AV_NOPTS_VALUE)

132 file->start_time = !fileno ? 0 :

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

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

135 return 0;

136 }

137

138 static int concat_read_close(AVFormatContext *avf)

139 {

140 ConcatContext *cat = avf->priv_data;

141 unsigned i;

142

143 if (cat->avf)

144 avformat_close_input(&cat->avf);

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

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

147 av_freep(&cat->files);

148 return 0;

149 }

150

151 static int concat_read_header(AVFormatContext *avf)

152 {

153 ConcatContext *cat = avf->priv_data;

154 uint8_t buf[4096];

155 uint8_t *cursor, *keyword;

156 int ret, line = 0, i;

157 unsigned nb_files_alloc = 0;

158 ConcatFile *file = NULL;

159 AVStream *st, *source_st;

160 int64_t time = 0;

161

162 while (1) {

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

164 break;

165 line++;

166 cursor = buf;

167 keyword = get_keyword(&cursor);

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

169 continue;

170

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

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

173 if (!filename) {

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

175 FAIL(AVERROR_INVALIDDATA);

176 }

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

178 FAIL(ret);

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

180 char *dur_str = get_keyword(&cursor);

181 int64_t dur;

182 if (!file) {

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

184 line);

185 FAIL(AVERROR_INVALIDDATA);

186 }

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

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

189 line, dur_str);

190 FAIL(ret);

191 }

192 file->duration = dur;

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

194 char *ver_kw = get_keyword(&cursor);

195 char *ver_val = get_keyword(&cursor);

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

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

198 FAIL(AVERROR_INVALIDDATA);

199 }

200 if (cat->safe < 0)

201 cat->safe = 1;

202 } else {

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

204 line, keyword);

205 FAIL(AVERROR_INVALIDDATA);

206 }

207 }

208 if (ret < 0)

209 FAIL(ret);

210

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

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

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

214 else

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

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

217 break;

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

219 }

220 if (i == cat->nb_files)

221 avf->duration = time;

222

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

224 FAIL(ret);

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

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

227 FAIL(AVERROR(ENOMEM));

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

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

230 FAIL(ret);

231 st->r_frame_rate = source_st->r_frame_rate;

232 st->avg_frame_rate = source_st->avg_frame_rate;

233 st->time_base = source_st->time_base;

234 st->sample_aspect_ratio = source_st->sample_aspect_ratio;

235 }

236

237 return 0;

238

239 fail:

240 concat_read_close(avf);

241 return ret;

242 }

243

244 static int open_next_file(AVFormatContext *avf)

245 {

246 ConcatContext *cat = avf->priv_data;

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

248

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

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

251

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

253 return AVERROR_EOF;

254 avformat_close_input(&cat->avf);

255 return open_file(avf, fileno);

256 }

257

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

259 {

260 ConcatContext *cat = avf->priv_data;

261 int ret;

262 int64_t delta;

263

264 while (1) {

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

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

267 break;

268 }

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

270 AV_TIME_BASE_Q,

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

272 if (pkt->pts != AV_NOPTS_VALUE)

273 pkt->pts += delta;

274 if (pkt->dts != AV_NOPTS_VALUE)

275 pkt->dts += delta;

276 return ret;

277 }

278

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

280 #define DEC AV_OPT_FLAG_DECODING_PARAM

281

282 static const AVOption options[] = {

283 { "safe", "enable safe mode",

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

285 { NULL }

286 };

287

288 static const AVClass concat_class = {

289 .class_name = "concat demuxer",

290 .item_name = av_default_item_name,

291 .option = options,

292 .version = LIBAVUTIL_VERSION_INT,

293 };

294

295

296 AVInputFormat ff_concat_demuxer = {

297 .name = "concat",

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

299 .priv_data_size = sizeof(ConcatContext),

300 .read_probe = concat_probe,

301 .read_header = concat_read_header,

302 .read_packet = concat_read_packet,

303 .read_close = concat_read_close,

304 .priv_class = &concat_class,

305 };

Generated on Sat May 25 2013 04:01:16 for FFmpeg by doxygen 1.8.2