xref: /third_party/ffmpeg/libavformat/mpeg.c (revision cabdff1a)
1/*
2 * MPEG-1/2 demuxer
3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
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
22#include "config_components.h"
23
24#include "libavutil/channel_layout.h"
25#include "avformat.h"
26#include "avio_internal.h"
27#include "demux.h"
28#include "internal.h"
29#include "mpeg.h"
30
31/*********************************************/
32/* demux code */
33
34#define MAX_SYNC_SIZE 100000
35
36static int check_pes(const uint8_t *p, const uint8_t *end)
37{
38    int pes1;
39    int pes2 = (p[3] & 0xC0) == 0x80 &&
40               (p[4] & 0xC0) != 0x40 &&
41               ((p[4] & 0xC0) == 0x00 ||
42                (p[4] & 0xC0) >> 2 == (p[6] & 0xF0));
43
44    for (p += 3; p < end && *p == 0xFF; p++) ;
45    if ((*p & 0xC0) == 0x40)
46        p += 2;
47
48    if ((*p & 0xF0) == 0x20)
49        pes1 = p[0] & p[2] & p[4] & 1;
50    else if ((*p & 0xF0) == 0x30)
51        pes1 = p[0] & p[2] & p[4] & p[5] & p[7] & p[9] & 1;
52    else
53        pes1 = *p == 0x0F;
54
55    return pes1 || pes2;
56}
57
58static int check_pack_header(const uint8_t *buf)
59{
60    return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
61}
62
63static int mpegps_probe(const AVProbeData *p)
64{
65    uint32_t code = -1;
66    int i;
67    int sys = 0, pspack = 0, priv1 = 0, vid = 0;
68    int audio = 0, invalid = 0, score = 0;
69    int endpes = 0;
70
71    for (i = 0; i < p->buf_size; i++) {
72        code = (code << 8) + p->buf[i];
73        if ((code & 0xffffff00) == 0x100) {
74            int len  = p->buf[i + 1] << 8 | p->buf[i + 2];
75            int pes  = endpes <= i && check_pes(p->buf + i, p->buf + p->buf_size);
76            int pack = check_pack_header(p->buf + i);
77
78            if (code == SYSTEM_HEADER_START_CODE)
79                sys++;
80            else if (code == PACK_START_CODE && pack)
81                pspack++;
82            else if ((code & 0xf0) == VIDEO_ID && pes) {
83                endpes = i + len;
84                vid++;
85            }
86            // skip pes payload to avoid start code emulation for private
87            // and audio streams
88            else if ((code & 0xe0) == AUDIO_ID &&  pes) {audio++; i+=len;}
89            else if (code == PRIVATE_STREAM_1  &&  pes) {priv1++; i+=len;}
90            else if (code == 0x1fd             &&  pes) vid++; //VC1
91
92            else if ((code & 0xf0) == VIDEO_ID && !pes) invalid++;
93            else if ((code & 0xe0) == AUDIO_ID && !pes) invalid++;
94            else if (code == PRIVATE_STREAM_1  && !pes) invalid++;
95        }
96    }
97
98    if (vid + audio > invalid + 1) /* invalid VDR files nd short PES streams */
99        score = AVPROBE_SCORE_EXTENSION / 2;
100
101//     av_log(NULL, AV_LOG_ERROR, "vid:%d aud:%d sys:%d pspack:%d invalid:%d size:%d \n",
102//            vid, audio, sys, pspack, invalid, p->buf_size);
103
104    if (sys > invalid && sys * 9 <= pspack * 10)
105        return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_EXTENSION + 2
106                                                     : AVPROBE_SCORE_EXTENSION / 2 + (audio + vid + pspack > 1); // 1 more than mp3
107    if (pspack > invalid && (priv1 + vid + audio) * 10 >= pspack * 9)
108        return pspack > 2 ? AVPROBE_SCORE_EXTENSION + 2
109                          : AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg
110    if ((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys &&
111        !pspack && p->buf_size > 2048 && vid + audio > invalid) /* PES stream */
112        return (audio > 12 || vid > 6 + 2 * invalid) ? AVPROBE_SCORE_EXTENSION + 2
113                                                     : AVPROBE_SCORE_EXTENSION / 2;
114
115    // 02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
116    // mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6
117    // Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618
118    return score;
119}
120
121typedef struct MpegDemuxContext {
122    int32_t header_state;
123    unsigned char psm_es_type[256];
124    int sofdec;
125    int dvd;
126    int imkh_cctv;
127    int raw_ac3;
128} MpegDemuxContext;
129
130static int mpegps_read_header(AVFormatContext *s)
131{
132    MpegDemuxContext *m = s->priv_data;
133    char buffer[7] = { 0 };
134    int64_t last_pos = avio_tell(s->pb);
135
136    m->header_state = 0xff;
137    s->ctx_flags   |= AVFMTCTX_NOHEADER;
138
139    avio_get_str(s->pb, 6, buffer, sizeof(buffer));
140    if (!memcmp("IMKH", buffer, 4)) {
141        m->imkh_cctv = 1;
142    } else if (!memcmp("Sofdec", buffer, 6)) {
143        m->sofdec = 1;
144    } else
145       avio_seek(s->pb, last_pos, SEEK_SET);
146
147    /* no need to do more */
148    return 0;
149}
150
151static int64_t get_pts(AVIOContext *pb, int c)
152{
153    uint8_t buf[5];
154    int ret;
155
156    buf[0] = c < 0 ? avio_r8(pb) : c;
157    ret = avio_read(pb, buf + 1, 4);
158    if (ret < 4)
159        return AV_NOPTS_VALUE;
160
161    return ff_parse_pes_pts(buf);
162}
163
164static int find_next_start_code(AVIOContext *pb, int *size_ptr,
165                                int32_t *header_state)
166{
167    unsigned int state, v;
168    int val, n;
169
170    state = *header_state;
171    n     = *size_ptr;
172    while (n > 0) {
173        if (avio_feof(pb))
174            break;
175        v = avio_r8(pb);
176        n--;
177        if (state == 0x000001) {
178            state = ((state << 8) | v) & 0xffffff;
179            val   = state;
180            goto found;
181        }
182        state = ((state << 8) | v) & 0xffffff;
183    }
184    val = -1;
185
186found:
187    *header_state = state;
188    *size_ptr     = n;
189    return val;
190}
191
192/**
193 * Extract stream types from a program stream map
194 * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
195 *
196 * @return number of bytes occupied by PSM in the bitstream
197 */
198static long mpegps_psm_parse(MpegDemuxContext *m, AVIOContext *pb)
199{
200    int psm_length, ps_info_length, es_map_length;
201
202    psm_length = avio_rb16(pb);
203    avio_r8(pb);
204    avio_r8(pb);
205    ps_info_length = avio_rb16(pb);
206
207    /* skip program_stream_info */
208    avio_skip(pb, ps_info_length);
209    /*es_map_length = */avio_rb16(pb);
210    /* Ignore es_map_length, trust psm_length */
211    es_map_length = psm_length - ps_info_length - 10;
212
213    /* at least one es available? */
214    while (es_map_length >= 4) {
215        unsigned char type      = avio_r8(pb);
216        unsigned char es_id     = avio_r8(pb);
217        uint16_t es_info_length = avio_rb16(pb);
218
219        /* remember mapping from stream id to stream type */
220        m->psm_es_type[es_id] = type;
221        /* skip program_stream_info */
222        avio_skip(pb, es_info_length);
223        es_map_length -= 4 + es_info_length;
224    }
225    avio_rb32(pb); /* crc32 */
226    return 2 + psm_length;
227}
228
229/* read the next PES header. Return its position in ppos
230 * (if not NULL), and its start code, pts and dts.
231 */
232static int mpegps_read_pes_header(AVFormatContext *s,
233                                  int64_t *ppos, int *pstart_code,
234                                  int64_t *ppts, int64_t *pdts)
235{
236    MpegDemuxContext *m = s->priv_data;
237    int len, size, startcode, c, flags, header_len;
238    int pes_ext, ext2_len, id_ext, skip;
239    int64_t pts, dts;
240    int64_t last_sync = avio_tell(s->pb);
241
242error_redo:
243    avio_seek(s->pb, last_sync, SEEK_SET);
244redo:
245    /* next start code (should be immediately after) */
246    m->header_state = 0xff;
247    size      = MAX_SYNC_SIZE;
248    startcode = find_next_start_code(s->pb, &size, &m->header_state);
249    last_sync = avio_tell(s->pb);
250    if (startcode < 0) {
251        if (avio_feof(s->pb))
252            return AVERROR_EOF;
253        // FIXME we should remember header_state
254        return FFERROR_REDO;
255    }
256
257    if (startcode == PACK_START_CODE)
258        goto redo;
259    if (startcode == SYSTEM_HEADER_START_CODE)
260        goto redo;
261    if (startcode == PADDING_STREAM) {
262        avio_skip(s->pb, avio_rb16(s->pb));
263        goto redo;
264    }
265    if (startcode == PRIVATE_STREAM_2) {
266        if (!m->sofdec) {
267            /* Need to detect whether this from a DVD or a 'Sofdec' stream */
268            int len = avio_rb16(s->pb);
269            int bytesread = 0;
270            uint8_t *ps2buf = av_malloc(len);
271
272            if (ps2buf) {
273                bytesread = avio_read(s->pb, ps2buf, len);
274
275                if (bytesread != len) {
276                    avio_skip(s->pb, len - bytesread);
277                } else {
278                    uint8_t *p = 0;
279                    if (len >= 6)
280                        p = memchr(ps2buf, 'S', len - 5);
281
282                    if (p)
283                        m->sofdec = !memcmp(p+1, "ofdec", 5);
284
285                    m->sofdec -= !m->sofdec;
286
287                    if (m->sofdec < 0) {
288                        if (len == 980  && ps2buf[0] == 0) {
289                            /* PCI structure? */
290                            uint32_t startpts = AV_RB32(ps2buf + 0x0d);
291                            uint32_t endpts = AV_RB32(ps2buf + 0x11);
292                            uint8_t hours = ((ps2buf[0x19] >> 4) * 10) + (ps2buf[0x19] & 0x0f);
293                            uint8_t mins  = ((ps2buf[0x1a] >> 4) * 10) + (ps2buf[0x1a] & 0x0f);
294                            uint8_t secs  = ((ps2buf[0x1b] >> 4) * 10) + (ps2buf[0x1b] & 0x0f);
295
296                            m->dvd = (hours <= 23 &&
297                                      mins  <= 59 &&
298                                      secs  <= 59 &&
299                                      (ps2buf[0x19] & 0x0f) < 10 &&
300                                      (ps2buf[0x1a] & 0x0f) < 10 &&
301                                      (ps2buf[0x1b] & 0x0f) < 10 &&
302                                      endpts >= startpts);
303                        } else if (len == 1018 && ps2buf[0] == 1) {
304                            /* DSI structure? */
305                            uint8_t hours = ((ps2buf[0x1d] >> 4) * 10) + (ps2buf[0x1d] & 0x0f);
306                            uint8_t mins  = ((ps2buf[0x1e] >> 4) * 10) + (ps2buf[0x1e] & 0x0f);
307                            uint8_t secs  = ((ps2buf[0x1f] >> 4) * 10) + (ps2buf[0x1f] & 0x0f);
308
309                            m->dvd = (hours <= 23 &&
310                                      mins  <= 59 &&
311                                      secs  <= 59 &&
312                                      (ps2buf[0x1d] & 0x0f) < 10 &&
313                                      (ps2buf[0x1e] & 0x0f) < 10 &&
314                                      (ps2buf[0x1f] & 0x0f) < 10);
315                        }
316                    }
317                }
318
319                av_free(ps2buf);
320
321                /* If this isn't a DVD packet or no memory
322                 * could be allocated, just ignore it.
323                 * If we did, move back to the start of the
324                 * packet (plus 'length' field) */
325                if (!m->dvd || avio_skip(s->pb, -(len + 2)) < 0) {
326                    /* Skip back failed.
327                     * This packet will be lost but that can't be helped
328                     * if we can't skip back
329                     */
330                    goto redo;
331                }
332            } else {
333                /* No memory */
334                avio_skip(s->pb, len);
335                goto redo;
336            }
337        } else if (!m->dvd) {
338            int len = avio_rb16(s->pb);
339            avio_skip(s->pb, len);
340            goto redo;
341        }
342    }
343    if (startcode == PROGRAM_STREAM_MAP) {
344        mpegps_psm_parse(m, s->pb);
345        goto redo;
346    }
347
348    /* find matching stream */
349    if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
350          (startcode >= 0x1e0 && startcode <= 0x1ef) ||
351          (startcode == 0x1bd) ||
352          (startcode == PRIVATE_STREAM_2) ||
353          (startcode == 0x1fd)))
354        goto redo;
355    if (ppos) {
356        *ppos = avio_tell(s->pb) - 4;
357    }
358    len = avio_rb16(s->pb);
359    pts =
360    dts = AV_NOPTS_VALUE;
361    if (startcode != PRIVATE_STREAM_2)
362    {
363    /* stuffing */
364    for (;;) {
365        if (len < 1)
366            goto error_redo;
367        c = avio_r8(s->pb);
368        len--;
369        /* XXX: for MPEG-1, should test only bit 7 */
370        if (c != 0xff)
371            break;
372    }
373    if ((c & 0xc0) == 0x40) {
374        /* buffer scale & size */
375        avio_r8(s->pb);
376        c    = avio_r8(s->pb);
377        len -= 2;
378    }
379    if ((c & 0xe0) == 0x20) {
380        dts  =
381        pts  = get_pts(s->pb, c);
382        len -= 4;
383        if (c & 0x10) {
384            dts  = get_pts(s->pb, -1);
385            len -= 5;
386        }
387    } else if ((c & 0xc0) == 0x80) {
388        /* mpeg 2 PES */
389        flags      = avio_r8(s->pb);
390        header_len = avio_r8(s->pb);
391        len       -= 2;
392        if (header_len > len)
393            goto error_redo;
394        len -= header_len;
395        if (flags & 0x80) {
396            dts         = pts = get_pts(s->pb, -1);
397            header_len -= 5;
398            if (flags & 0x40) {
399                dts         = get_pts(s->pb, -1);
400                header_len -= 5;
401            }
402        }
403        if (flags & 0x3f && header_len == 0) {
404            flags &= 0xC0;
405            av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
406        }
407        if (flags & 0x01) { /* PES extension */
408            pes_ext = avio_r8(s->pb);
409            header_len--;
410            /* Skip PES private data, program packet sequence counter
411             * and P-STD buffer */
412            skip  = (pes_ext >> 4) & 0xb;
413            skip += skip & 0x9;
414            if (pes_ext & 0x40 || skip > header_len) {
415                av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
416                pes_ext = skip = 0;
417            }
418            avio_skip(s->pb, skip);
419            header_len -= skip;
420
421            if (pes_ext & 0x01) { /* PES extension 2 */
422                ext2_len = avio_r8(s->pb);
423                header_len--;
424                if ((ext2_len & 0x7f) > 0) {
425                    id_ext = avio_r8(s->pb);
426                    if ((id_ext & 0x80) == 0)
427                        startcode = ((startcode & 0xff) << 8) | id_ext;
428                    header_len--;
429                }
430            }
431        }
432        if (header_len < 0)
433            goto error_redo;
434        avio_skip(s->pb, header_len);
435    } else if (c != 0xf)
436        goto redo;
437    }
438
439    if (startcode == PRIVATE_STREAM_1) {
440        int ret = ffio_ensure_seekback(s->pb, 2);
441
442        if (ret < 0)
443            return ret;
444
445        startcode = avio_r8(s->pb);
446        m->raw_ac3 = 0;
447        if (startcode == 0x0b) {
448            if (avio_r8(s->pb) == 0x77) {
449                startcode = 0x80;
450                m->raw_ac3 = 1;
451                avio_skip(s->pb, -2);
452            } else {
453                avio_skip(s->pb, -1);
454            }
455        } else {
456            len--;
457        }
458    }
459    if (len < 0)
460        goto error_redo;
461    if (dts != AV_NOPTS_VALUE && ppos) {
462        int i;
463        for (i = 0; i < s->nb_streams; i++) {
464            if (startcode == s->streams[i]->id &&
465                (s->pb->seekable & AVIO_SEEKABLE_NORMAL) /* index useless on streams anyway */) {
466                ff_reduce_index(s, i);
467                av_add_index_entry(s->streams[i], *ppos, dts, 0, 0,
468                                   AVINDEX_KEYFRAME /* FIXME keyframe? */);
469            }
470        }
471    }
472
473    *pstart_code = startcode;
474    *ppts        = pts;
475    *pdts        = dts;
476    return len;
477}
478
479static int mpegps_read_packet(AVFormatContext *s,
480                              AVPacket *pkt)
481{
482    MpegDemuxContext *m = s->priv_data;
483    AVStream *st;
484    FFStream *sti;
485    int len, startcode, i, es_type, ret;
486    int pcm_dvd = 0;
487    int request_probe= 0;
488    enum AVCodecID codec_id = AV_CODEC_ID_NONE;
489    enum AVMediaType type;
490    int64_t pts, dts, dummy_pos; // dummy_pos is needed for the index building to work
491
492redo:
493    len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
494    if (len < 0)
495        return len;
496
497    if (startcode >= 0x80 && startcode <= 0xcf) {
498        if (len < 4)
499            goto skip;
500
501        if (!m->raw_ac3) {
502            /* audio: skip header */
503            avio_skip(s->pb, 3);
504            len -= 3;
505            if (startcode >= 0xb0 && startcode <= 0xbf) {
506                /* MLP/TrueHD audio has a 4-byte header */
507                avio_r8(s->pb);
508                len--;
509            } else if (startcode >= 0xa0 && startcode <= 0xaf) {
510                ret = ffio_ensure_seekback(s->pb, 3);
511                if (ret < 0)
512                    return ret;
513                pcm_dvd = (avio_rb24(s->pb) & 0xFF) == 0x80;
514                avio_skip(s->pb, -3);
515            }
516        }
517    }
518
519    /* now find stream */
520    for (i = 0; i < s->nb_streams; i++) {
521        st = s->streams[i];
522        if (st->id == startcode)
523            goto found;
524    }
525
526    es_type = m->psm_es_type[startcode & 0xff];
527    if (es_type == STREAM_TYPE_VIDEO_MPEG1) {
528        codec_id = AV_CODEC_ID_MPEG2VIDEO;
529        type     = AVMEDIA_TYPE_VIDEO;
530    } else if (es_type == STREAM_TYPE_VIDEO_MPEG2) {
531        codec_id = AV_CODEC_ID_MPEG2VIDEO;
532        type     = AVMEDIA_TYPE_VIDEO;
533    } else if (es_type == STREAM_TYPE_AUDIO_MPEG1 ||
534               es_type == STREAM_TYPE_AUDIO_MPEG2) {
535        codec_id = AV_CODEC_ID_MP3;
536        type     = AVMEDIA_TYPE_AUDIO;
537    } else if (es_type == STREAM_TYPE_AUDIO_AAC) {
538        codec_id = AV_CODEC_ID_AAC;
539        type     = AVMEDIA_TYPE_AUDIO;
540    } else if (es_type == STREAM_TYPE_VIDEO_MPEG4) {
541        codec_id = AV_CODEC_ID_MPEG4;
542        type     = AVMEDIA_TYPE_VIDEO;
543    } else if (es_type == STREAM_TYPE_VIDEO_H264) {
544        codec_id = AV_CODEC_ID_H264;
545        type     = AVMEDIA_TYPE_VIDEO;
546    } else if (es_type == STREAM_TYPE_VIDEO_HEVC) {
547        codec_id = AV_CODEC_ID_HEVC;
548        type     = AVMEDIA_TYPE_VIDEO;
549    } else if (es_type == STREAM_TYPE_AUDIO_AC3) {
550        codec_id = AV_CODEC_ID_AC3;
551        type     = AVMEDIA_TYPE_AUDIO;
552    } else if (m->imkh_cctv && es_type == 0x91) {
553        codec_id = AV_CODEC_ID_PCM_MULAW;
554        type     = AVMEDIA_TYPE_AUDIO;
555    } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
556        static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
557        unsigned char buf[8];
558
559        avio_read(s->pb, buf, 8);
560        avio_seek(s->pb, -8, SEEK_CUR);
561        if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
562            codec_id = AV_CODEC_ID_CAVS;
563        else
564            request_probe= 1;
565        type = AVMEDIA_TYPE_VIDEO;
566    } else if (startcode == PRIVATE_STREAM_2) {
567        type = AVMEDIA_TYPE_DATA;
568        codec_id = AV_CODEC_ID_DVD_NAV;
569    } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
570        type     = AVMEDIA_TYPE_AUDIO;
571        if (m->sofdec > 0) {
572            codec_id = AV_CODEC_ID_ADPCM_ADX;
573            // Auto-detect AC-3
574            request_probe = 50;
575        } else if (m->imkh_cctv && startcode == 0x1c0 && len > 80) {
576            codec_id = AV_CODEC_ID_PCM_ALAW;
577            request_probe = 50;
578        } else {
579            codec_id = AV_CODEC_ID_MP2;
580            if (m->imkh_cctv)
581                request_probe = 25;
582        }
583    } else if (startcode >= 0x80 && startcode <= 0x87) {
584        type     = AVMEDIA_TYPE_AUDIO;
585        codec_id = AV_CODEC_ID_AC3;
586    } else if ((startcode >= 0x88 && startcode <= 0x8f) ||
587               (startcode >= 0x98 && startcode <= 0x9f)) {
588        /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
589        type     = AVMEDIA_TYPE_AUDIO;
590        codec_id = AV_CODEC_ID_DTS;
591    } else if (startcode >= 0xa0 && startcode <= 0xaf) {
592        type     = AVMEDIA_TYPE_AUDIO;
593        if (!pcm_dvd) {
594            codec_id = AV_CODEC_ID_MLP;
595        } else {
596            codec_id = AV_CODEC_ID_PCM_DVD;
597        }
598    } else if (startcode >= 0xb0 && startcode <= 0xbf) {
599        type     = AVMEDIA_TYPE_AUDIO;
600        codec_id = AV_CODEC_ID_TRUEHD;
601    } else if (startcode >= 0xc0 && startcode <= 0xcf) {
602        /* Used for both AC-3 and E-AC-3 in EVOB files */
603        type     = AVMEDIA_TYPE_AUDIO;
604        codec_id = AV_CODEC_ID_AC3;
605    } else if (startcode >= 0x20 && startcode <= 0x3f) {
606        type     = AVMEDIA_TYPE_SUBTITLE;
607        codec_id = AV_CODEC_ID_DVD_SUBTITLE;
608    } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
609        type     = AVMEDIA_TYPE_VIDEO;
610        codec_id = AV_CODEC_ID_VC1;
611    } else {
612skip:
613        /* skip packet */
614        avio_skip(s->pb, len);
615        goto redo;
616    }
617    /* no stream found: add a new stream */
618    st = avformat_new_stream(s, NULL);
619    if (!st)
620        goto skip;
621    sti = ffstream(st);
622    st->id                = startcode;
623    st->codecpar->codec_type = type;
624    st->codecpar->codec_id   = codec_id;
625    if (   st->codecpar->codec_id == AV_CODEC_ID_PCM_MULAW
626        || st->codecpar->codec_id == AV_CODEC_ID_PCM_ALAW) {
627        st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
628        st->codecpar->sample_rate = 8000;
629    }
630    sti->request_probe = request_probe;
631    sti->need_parsing  = AVSTREAM_PARSE_FULL;
632
633found:
634    if (st->discard >= AVDISCARD_ALL)
635        goto skip;
636    if (startcode >= 0xa0 && startcode <= 0xaf) {
637      if (st->codecpar->codec_id == AV_CODEC_ID_MLP) {
638            if (len < 6)
639                goto skip;
640            avio_skip(s->pb, 6);
641            len -=6;
642      }
643    }
644    ret = av_get_packet(s->pb, pkt, len);
645
646    pkt->pts          = pts;
647    pkt->dts          = dts;
648    pkt->pos          = dummy_pos;
649    pkt->stream_index = st->index;
650
651    if (s->debug & FF_FDEBUG_TS)
652        av_log(s, AV_LOG_DEBUG, "%d: pts=%0.3f dts=%0.3f size=%d\n",
653            pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,
654            pkt->size);
655
656    return (ret < 0) ? ret : 0;
657}
658
659static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
660                               int64_t *ppos, int64_t pos_limit)
661{
662    int len, startcode;
663    int64_t pos, pts, dts;
664
665    pos = *ppos;
666    if (avio_seek(s->pb, pos, SEEK_SET) < 0)
667        return AV_NOPTS_VALUE;
668
669    for (;;) {
670        len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
671        if (len < 0) {
672            if (s->debug & FF_FDEBUG_TS)
673                av_log(s, AV_LOG_DEBUG, "none (ret=%d)\n", len);
674            return AV_NOPTS_VALUE;
675        }
676        if (startcode == s->streams[stream_index]->id &&
677            dts != AV_NOPTS_VALUE) {
678            break;
679        }
680        avio_skip(s->pb, len);
681    }
682    if (s->debug & FF_FDEBUG_TS)
683        av_log(s, AV_LOG_DEBUG, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",
684            pos, dts, dts / 90000.0);
685    *ppos = pos;
686    return dts;
687}
688
689const AVInputFormat ff_mpegps_demuxer = {
690    .name           = "mpeg",
691    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),
692    .priv_data_size = sizeof(MpegDemuxContext),
693    .read_probe     = mpegps_probe,
694    .read_header    = mpegps_read_header,
695    .read_packet    = mpegps_read_packet,
696    .read_timestamp = mpegps_read_dts,
697    .flags          = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
698};
699
700#if CONFIG_VOBSUB_DEMUXER
701
702#include "subtitles.h"
703#include "libavutil/avassert.h"
704#include "libavutil/bprint.h"
705#include "libavutil/opt.h"
706
707#define REF_STRING "# VobSub index file,"
708#define MAX_LINE_SIZE 2048
709
710typedef struct VobSubDemuxContext {
711    const AVClass *class;
712    AVFormatContext *sub_ctx;
713    FFDemuxSubtitlesQueue q[32];
714    char *sub_name;
715} VobSubDemuxContext;
716
717static int vobsub_probe(const AVProbeData *p)
718{
719    if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))
720        return AVPROBE_SCORE_MAX;
721    return 0;
722}
723
724static int vobsub_read_close(AVFormatContext *s)
725{
726    VobSubDemuxContext *vobsub = s->priv_data;
727    int i;
728
729    for (i = 0; i < s->nb_streams; i++)
730        ff_subtitles_queue_clean(&vobsub->q[i]);
731    avformat_close_input(&vobsub->sub_ctx);
732    return 0;
733}
734
735static int vobsub_read_header(AVFormatContext *s)
736{
737    int i, ret = 0, header_parsed = 0, langidx = 0;
738    VobSubDemuxContext *vobsub = s->priv_data;
739    const AVInputFormat *iformat;
740    size_t fname_len;
741    AVBPrint header;
742    int64_t delay = 0;
743    AVStream *st = NULL;
744    int stream_id = -1;
745    char id[64] = {0};
746    char alt[MAX_LINE_SIZE] = {0};
747
748    if (!vobsub->sub_name) {
749        char *ext;
750        vobsub->sub_name = av_strdup(s->url);
751        if (!vobsub->sub_name) {
752            return AVERROR(ENOMEM);
753        }
754
755        fname_len = strlen(vobsub->sub_name);
756        ext = vobsub->sub_name - 3 + fname_len;
757        if (fname_len < 4 || *(ext - 1) != '.') {
758            av_log(s, AV_LOG_ERROR, "The input index filename is too short "
759                   "to guess the associated .SUB file\n");
760            return AVERROR_INVALIDDATA;
761        }
762        memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);
763        av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->url, vobsub->sub_name);
764    }
765
766    if (!(iformat = av_find_input_format("mpeg"))) {
767        return AVERROR_DEMUXER_NOT_FOUND;
768    }
769
770    vobsub->sub_ctx = avformat_alloc_context();
771    if (!vobsub->sub_ctx) {
772        return AVERROR(ENOMEM);
773    }
774
775    if ((ret = ff_copy_whiteblacklists(vobsub->sub_ctx, s)) < 0)
776        return ret;
777
778    ret = avformat_open_input(&vobsub->sub_ctx, vobsub->sub_name, iformat, NULL);
779    if (ret < 0) {
780        av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", vobsub->sub_name);
781        return ret;
782    }
783
784    av_bprint_init(&header, 0, INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE);
785
786    while (!avio_feof(s->pb)) {
787        char line[MAX_LINE_SIZE];
788        int len = ff_get_line(s->pb, line, sizeof(line));
789
790        if (!len)
791            break;
792
793        line[strcspn(line, "\r\n")] = 0;
794
795        if (!strncmp(line, "id:", 3)) {
796            if (sscanf(line, "id: %63[^,], index: %u", id, &stream_id) != 2) {
797                av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "
798                       "assuming 'id: und, index: 0'\n", line);
799                strcpy(id, "und");
800                stream_id = 0;
801            }
802
803            if (stream_id >= FF_ARRAY_ELEMS(vobsub->q)) {
804                av_log(s, AV_LOG_ERROR, "Maximum number of subtitles streams reached\n");
805                ret = AVERROR(EINVAL);
806                goto end;
807            }
808
809            header_parsed = 1;
810            alt[0] = '\0';
811            /* We do not create the stream immediately to avoid adding empty
812             * streams. See the following timestamp entry. */
813
814            av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);
815
816        } else if (!strncmp(line, "timestamp:", 10)) {
817            AVPacket *sub;
818            int hh, mm, ss, ms;
819            int64_t pos, timestamp;
820            const char *p = line + 10;
821
822            if (stream_id == -1) {
823                av_log(s, AV_LOG_ERROR, "Timestamp declared before any stream\n");
824                ret = AVERROR_INVALIDDATA;
825                goto end;
826            }
827
828            if (!st || st->id != stream_id) {
829                st = avformat_new_stream(s, NULL);
830                if (!st) {
831                    ret = AVERROR(ENOMEM);
832                    goto end;
833                }
834                st->id = stream_id;
835                st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
836                st->codecpar->codec_id   = AV_CODEC_ID_DVD_SUBTITLE;
837                avpriv_set_pts_info(st, 64, 1, 1000);
838                av_dict_set(&st->metadata, "language", id, 0);
839                if (alt[0])
840                    av_dict_set(&st->metadata, "title", alt, 0);
841            }
842
843            if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"SCNx64,
844                       &hh, &mm, &ss, &ms, &pos) != 5) {
845                av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "
846                       "abort parsing\n", line);
847                ret = AVERROR_INVALIDDATA;
848                goto end;
849            }
850            timestamp = (hh*3600LL + mm*60LL + ss) * 1000LL + ms + delay;
851            timestamp = av_rescale_q(timestamp, av_make_q(1, 1000), st->time_base);
852
853            sub = ff_subtitles_queue_insert(&vobsub->q[s->nb_streams - 1], "", 0, 0);
854            if (!sub) {
855                ret = AVERROR(ENOMEM);
856                goto end;
857            }
858            sub->pos = pos;
859            sub->pts = timestamp;
860            sub->stream_index = s->nb_streams - 1;
861
862        } else if (!strncmp(line, "alt:", 4)) {
863            const char *p = line + 4;
864
865            while (*p == ' ')
866                p++;
867            av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", stream_id, p);
868            av_strlcpy(alt, p, sizeof(alt));
869            header_parsed = 1;
870
871        } else if (!strncmp(line, "delay:", 6)) {
872            int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;
873            const char *p = line + 6;
874
875            while (*p == ' ')
876                p++;
877            if (*p == '-' || *p == '+') {
878                sign = *p == '-' ? -1 : 1;
879                p++;
880            }
881            sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);
882            delay = ((hh*3600LL + mm*60LL + ss) * 1000LL + ms) * sign;
883
884        } else if (!strncmp(line, "langidx:", 8)) {
885            const char *p = line + 8;
886
887            if (sscanf(p, "%d", &langidx) != 1)
888                av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");
889
890        } else if (!header_parsed) {
891            if (line[0] && line[0] != '#')
892                av_bprintf(&header, "%s\n", line);
893        }
894    }
895
896    if (langidx < s->nb_streams)
897        s->streams[langidx]->disposition |= AV_DISPOSITION_DEFAULT;
898
899    for (i = 0; i < s->nb_streams; i++) {
900        vobsub->q[i].sort = SUB_SORT_POS_TS;
901        vobsub->q[i].keep_duplicates = 1;
902        ff_subtitles_queue_finalize(s, &vobsub->q[i]);
903    }
904
905    if (!av_bprint_is_complete(&header)) {
906        ret = AVERROR(ENOMEM);
907        goto end;
908    }
909    for (i = 0; i < s->nb_streams; i++) {
910        AVCodecParameters *par = s->streams[i]->codecpar;
911        ret = ff_alloc_extradata(par, header.len);
912        if (ret < 0) {
913            goto end;
914        }
915        memcpy(par->extradata, header.str, header.len);
916    }
917end:
918    av_bprint_finalize(&header, NULL);
919    return ret;
920}
921
922static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
923{
924    VobSubDemuxContext *vobsub = s->priv_data;
925    FFDemuxSubtitlesQueue *q;
926    AVIOContext *pb = vobsub->sub_ctx->pb;
927    int ret, psize, total_read = 0, i;
928
929    int64_t min_ts = INT64_MAX;
930    int sid = 0;
931    for (i = 0; i < s->nb_streams; i++) {
932        FFDemuxSubtitlesQueue *tmpq = &vobsub->q[i];
933        int64_t ts;
934        av_assert0(tmpq->nb_subs);
935
936        if (tmpq->current_sub_idx >= tmpq->nb_subs)
937            continue;
938
939        ts = tmpq->subs[tmpq->current_sub_idx]->pts;
940        if (ts < min_ts) {
941            min_ts = ts;
942            sid = i;
943        }
944    }
945    q = &vobsub->q[sid];
946    /* The returned packet will have size zero,
947     * so that it can be directly used with av_grow_packet. */
948    ret = ff_subtitles_queue_read_packet(q, pkt);
949    if (ret < 0)
950        return ret;
951
952    /* compute maximum packet size using the next packet position. This is
953     * useful when the len in the header is non-sense */
954    if (q->current_sub_idx < q->nb_subs) {
955        psize = q->subs[q->current_sub_idx]->pos - pkt->pos;
956    } else {
957        int64_t fsize = avio_size(pb);
958        psize = fsize < 0 ? 0xffff : fsize - pkt->pos;
959    }
960
961    avio_seek(pb, pkt->pos, SEEK_SET);
962
963    do {
964        int n, to_read, startcode;
965        int64_t pts, dts;
966        int64_t old_pos = avio_tell(pb), new_pos;
967        int pkt_size;
968
969        ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
970        if (ret < 0) {
971            if (pkt->size) // raise packet even if incomplete
972                break;
973            return ret;
974        }
975        to_read = ret & 0xffff;
976        new_pos = avio_tell(pb);
977        pkt_size = ret + (new_pos - old_pos);
978
979        /* this prevents reads above the current packet */
980        if (total_read + pkt_size > psize)
981            break;
982        total_read += pkt_size;
983
984        /* the current chunk doesn't match the stream index (unlikely) */
985        if ((startcode & 0x1f) != s->streams[pkt->stream_index]->id)
986            break;
987
988        ret = av_grow_packet(pkt, to_read);
989        if (ret < 0)
990            return ret;
991
992        n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
993        if (n < to_read)
994            pkt->size -= to_read - n;
995    } while (total_read < psize);
996
997    return 0;
998}
999
1000static int vobsub_read_seek(AVFormatContext *s, int stream_index,
1001                            int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
1002{
1003    VobSubDemuxContext *vobsub = s->priv_data;
1004
1005    /* Rescale requested timestamps based on the first stream (timebase is the
1006     * same for all subtitles stream within a .idx/.sub). Rescaling is done just
1007     * like in avformat_seek_file(). */
1008    if (stream_index == -1 && s->nb_streams != 1) {
1009        int i, ret = 0;
1010        AVRational time_base = s->streams[0]->time_base;
1011        ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base);
1012        min_ts = av_rescale_rnd(min_ts, time_base.den,
1013                                time_base.num * (int64_t)AV_TIME_BASE,
1014                                AV_ROUND_UP   | AV_ROUND_PASS_MINMAX);
1015        max_ts = av_rescale_rnd(max_ts, time_base.den,
1016                                time_base.num * (int64_t)AV_TIME_BASE,
1017                                AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);
1018        for (i = 0; i < s->nb_streams; i++) {
1019            int r = ff_subtitles_queue_seek(&vobsub->q[i], s, stream_index,
1020                                            min_ts, ts, max_ts, flags);
1021            if (r < 0)
1022                ret = r;
1023        }
1024        return ret;
1025    }
1026
1027    if (stream_index == -1) // only 1 stream
1028        stream_index = 0;
1029    return ff_subtitles_queue_seek(&vobsub->q[stream_index], s, stream_index,
1030                                   min_ts, ts, max_ts, flags);
1031}
1032
1033static const AVOption options[] = {
1034    { "sub_name", "URI for .sub file", offsetof(VobSubDemuxContext, sub_name), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_DECODING_PARAM },
1035    { NULL }
1036};
1037
1038static const AVClass vobsub_demuxer_class = {
1039    .class_name = "vobsub",
1040    .item_name  = av_default_item_name,
1041    .option     = options,
1042    .version    = LIBAVUTIL_VERSION_INT,
1043};
1044
1045const AVInputFormat ff_vobsub_demuxer = {
1046    .name           = "vobsub",
1047    .long_name      = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),
1048    .priv_data_size = sizeof(VobSubDemuxContext),
1049    .flags_internal = FF_FMT_INIT_CLEANUP,
1050    .read_probe     = vobsub_probe,
1051    .read_header    = vobsub_read_header,
1052    .read_packet    = vobsub_read_packet,
1053    .read_seek2     = vobsub_read_seek,
1054    .read_close     = vobsub_read_close,
1055    .flags          = AVFMT_SHOW_IDS,
1056    .extensions     = "idx",
1057    .priv_class     = &vobsub_demuxer_class,
1058};
1059#endif
1060