Unified · Split
| @@ -39,6 +39,9 @@ · 38 unmodified lines | ||
| 39 | 39 | |
| 40 | 40 | typedef struct MP3DecContext { |
| 41 | 41 | int xing_toc; |
| 42 | + unsigned frames; /* Total number of frames in file */ | |
| 43 | + unsigned size; /* Total number of bytes in the stream */ | |
| 44 | + int is_cbr; | |
| 42 | 45 | } MP3DecContext; |
| 43 | 46 | |
| 44 | 47 | /* mp3 read */ |
| @@ -125,18 +128,60 @@ static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration · 80 unmodified lines | ||
| 125 | 128 | mp3->xing_toc = 1; |
| 126 | 129 | } |
| 127 | 130 | |
| 131 | + | |
| 132 | +static void mp3_parse_info_tag(AVFormatContext *s, AVStream *st, | |
| 133 | + MPADecodeHeader *c, uint32_t spf) | |
| 134 | +{ | |
| 135 | + uint32_t v; | |
| 136 | + MP3DecContext *mp3 = s->priv_data; | |
| 137 | + const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}}; | |
| 138 | + | |
| 139 | + /* Check for Xing / Info tag */ | |
| 140 | + avio_skip(s->pb, xing_offtbl[c->lsf == 1][c->nb_channels == 1]); | |
| 141 | + v = avio_rb32(s->pb); | |
| 142 | + mp3->is_cbr = v == MKBETAG('I', 'n', 'f', 'o'); | |
| 143 | + if (v == MKBETAG('X', 'i', 'n', 'g') || mp3->is_cbr) { | |
| 144 | + v = avio_rb32(s->pb); | |
| 145 | + if (v & XING_FLAG_FRAMES) | |
| 146 | + mp3->frames = avio_rb32(s->pb); | |
| 147 | + if (v & XING_FLAG_SIZE) | |
| 148 | + mp3->size = avio_rb32(s->pb); | |
| 149 | + if (v & XING_FLAG_TOC && mp3->frames) | |
| 150 | + read_xing_toc(s, mp3->size, | |
| 151 | + av_rescale_q(mp3->frames, | |
| 152 | + (AVRational){spf, c->sample_rate}, | |
| 153 | + st->time_base)); | |
| 154 | + } | |
| 155 | +} | |
| 156 | + | |
| 157 | +static void mp3_parse_vbri_tag(AVFormatContext *s, AVStream *st, int64_t base) | |
| 158 | +{ | |
| 159 | + uint32_t v; | |
| 160 | + MP3DecContext *mp3 = s->priv_data; | |
| 161 | + | |
| 162 | + /* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */ | |
| 163 | + avio_seek(s->pb, base + 4 + 32, SEEK_SET); | |
| 164 | + v = avio_rb32(s->pb); | |
| 165 | + if (v == MKBETAG('V', 'B', 'R', 'I')) { | |
| 166 | + /* Check tag version */ | |
| 167 | + if (avio_rb16(s->pb) == 1) { | |
| 168 | + /* skip delay and quality */ | |
| 169 | + avio_skip(s->pb, 4); | |
| 170 | + mp3->size = avio_rb32(s->pb); | |
| 171 | + mp3->frames = avio_rb32(s->pb); | |
| 172 | + } | |
| 173 | + } | |
| 174 | +} | |
| 175 | + | |
| 128 | 176 | /** |
| 129 | 177 | * Try to find Xing/Info/VBRI tags and compute duration from info therein |
| 130 | 178 | */ |
| 131 | 179 | static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base) |
| 132 | 180 | { |
| 133 | 181 | uint32_t v, spf; |
| 134 | − unsigned frames = 0; /* Total number of frames in file */ | |
| 135 | − unsigned size = 0; /* Total number of bytes in the stream */ | |
| 136 | − const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}}; | |
| 137 | 182 | MPADecodeHeader c; |
| 138 | 183 | int vbrtag_size = 0; |
| 139 | − int is_cbr; | |
| 184 | + MP3DecContext *mp3 = s->priv_data; | |
| 140 | 185 | |
| 141 | 186 | v = avio_rb32(s->pb); |
| 142 | 187 | if(ff_mpa_check_header(v) < 0) |
| @@ -149,45 +194,23 @@ static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base) · 6 unmodified lines | ||
| 149 | 194 | |
| 150 | 195 | spf = c.lsf ? 576 : 1152; /* Samples per frame, layer 3 */ |
| 151 | 196 | |
| 152 | − /* Check for Xing / Info tag */ | |
| 153 | − avio_skip(s->pb, xing_offtbl[c.lsf == 1][c.nb_channels == 1]); | |
| 154 | − v = avio_rb32(s->pb); | |
| 155 | − is_cbr = v == MKBETAG('I', 'n', 'f', 'o'); | |
| 156 | − if (v == MKBETAG('X', 'i', 'n', 'g') || is_cbr) { | |
| 157 | − v = avio_rb32(s->pb); | |
| 158 | − if(v & XING_FLAG_FRAMES) | |
| 159 | − frames = avio_rb32(s->pb); | |
| 160 | − if(v & XING_FLAG_SIZE) | |
| 161 | − size = avio_rb32(s->pb); | |
| 162 | − if (v & XING_FLAG_TOC && frames) | |
| 163 | − read_xing_toc(s, size, av_rescale_q(frames, (AVRational){spf, c.sample_rate}, | |
| 164 | − st->time_base)); | |
| 165 | − } | |
| 197 | + mp3->frames = 0; | |
| 198 | + mp3->size = 0; | |
| 166 | 199 | |
| 167 | − /* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */ | |
| 168 | − avio_seek(s->pb, base + 4 + 32, SEEK_SET); | |
| 169 | − v = avio_rb32(s->pb); | |
| 170 | − if(v == MKBETAG('V', 'B', 'R', 'I')) { | |
| 171 | − /* Check tag version */ | |
| 172 | − if(avio_rb16(s->pb) == 1) { | |
| 173 | − /* skip delay and quality */ | |
| 174 | − avio_skip(s->pb, 4); | |
| 175 | − size = avio_rb32(s->pb); | |
| 176 | − frames = avio_rb32(s->pb); | |
| 177 | − } | |
| 178 | − } | |
| 200 | + mp3_parse_info_tag(s, st, &c, spf); | |
| 201 | + mp3_parse_vbri_tag(s, st, base); | |
| 179 | 202 | |
| 180 | − if(!frames && !size) | |
| 203 | + if (!mp3->frames && !mp3->size) | |
| 181 | 204 | return -1; |
| 182 | 205 | |
| 183 | 206 | /* Skip the vbr tag frame */ |
| 184 | 207 | avio_seek(s->pb, base + vbrtag_size, SEEK_SET); |
| 185 | 208 | |
| 186 | − if(frames) | |
| 187 | − st->duration = av_rescale_q(frames, (AVRational){spf, c.sample_rate}, | |
| 209 | + if (mp3->frames) | |
| 210 | + st->duration = av_rescale_q(mp3->frames, (AVRational){spf, c.sample_rate}, | |
| 188 | 211 | st->time_base); |
| 189 | − if (size && frames && !is_cbr) | |
| 190 | − st->codec->bit_rate = av_rescale(size, 8 * c.sample_rate, frames * (int64_t)spf); | |
| 212 | + if (mp3->size && mp3->frames && !mp3->is_cbr) | |
| 213 | + st->codec->bit_rate = av_rescale(mp3->size, 8 * c.sample_rate, mp3->frames * (int64_t)spf); | |
| 191 | 214 | |
| 192 | 215 | return 0; |
| 193 | 216 | } |