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libavformat/gxf.c

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00001 /*
00002  * GXF demuxer.
00003  * Copyright (c) 2006 Reimar Doeffinger
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavutil/common.h"
00023 #include "avformat.h"
00024 #include "internal.h"
00025 #include "gxf.h"
00026 
00027 struct gxf_stream_info {
00028     int64_t first_field;
00029     int64_t last_field;
00030     AVRational frames_per_second;
00031     int32_t fields_per_frame;
00032 };
00033 
00041 static int parse_packet_header(AVIOContext *pb, GXFPktType *type, int *length) {
00042     if (avio_rb32(pb))
00043         return 0;
00044     if (avio_r8(pb) != 1)
00045         return 0;
00046     *type = avio_r8(pb);
00047     *length = avio_rb32(pb);
00048     if ((*length >> 24) || *length < 16)
00049         return 0;
00050     *length -= 16;
00051     if (avio_rb32(pb))
00052         return 0;
00053     if (avio_r8(pb) != 0xe1)
00054         return 0;
00055     if (avio_r8(pb) != 0xe2)
00056         return 0;
00057     return 1;
00058 }
00059 
00063 static int gxf_probe(AVProbeData *p) {
00064     static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
00065     static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
00066     if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
00067         !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
00068         return AVPROBE_SCORE_MAX;
00069     return 0;
00070 }
00071 
00078 static int get_sindex(AVFormatContext *s, int id, int format) {
00079     int i;
00080     AVStream *st = NULL;
00081     i = ff_find_stream_index(s, id);
00082     if (i >= 0)
00083         return i;
00084     st = avformat_new_stream(s, NULL);
00085     if (!st)
00086         return AVERROR(ENOMEM);
00087     st->id = id;
00088     switch (format) {
00089         case 3:
00090         case 4:
00091             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00092             st->codec->codec_id = CODEC_ID_MJPEG;
00093             break;
00094         case 13:
00095         case 15:
00096             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00097             st->codec->codec_id = CODEC_ID_DVVIDEO;
00098             break;
00099         case 14:
00100         case 16:
00101             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00102             st->codec->codec_id = CODEC_ID_DVVIDEO;
00103             break;
00104         case 11:
00105         case 12:
00106         case 20:
00107             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00108             st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
00109             st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
00110             break;
00111         case 22:
00112         case 23:
00113             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00114             st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
00115             st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
00116             break;
00117         case 9:
00118             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00119             st->codec->codec_id = CODEC_ID_PCM_S24LE;
00120             st->codec->channels = 1;
00121             st->codec->sample_rate = 48000;
00122             st->codec->bit_rate = 3 * 1 * 48000 * 8;
00123             st->codec->block_align = 3 * 1;
00124             st->codec->bits_per_coded_sample = 24;
00125             break;
00126         case 10:
00127             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00128             st->codec->codec_id = CODEC_ID_PCM_S16LE;
00129             st->codec->channels = 1;
00130             st->codec->sample_rate = 48000;
00131             st->codec->bit_rate = 2 * 1 * 48000 * 8;
00132             st->codec->block_align = 2 * 1;
00133             st->codec->bits_per_coded_sample = 16;
00134             break;
00135         case 17:
00136             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00137             st->codec->codec_id = CODEC_ID_AC3;
00138             st->codec->channels = 2;
00139             st->codec->sample_rate = 48000;
00140             break;
00141         // timecode tracks:
00142         case 7:
00143         case 8:
00144         case 24:
00145             st->codec->codec_type = AVMEDIA_TYPE_DATA;
00146             st->codec->codec_id = CODEC_ID_NONE;
00147             break;
00148         default:
00149             st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
00150             st->codec->codec_id = CODEC_ID_NONE;
00151             break;
00152     }
00153     return s->nb_streams - 1;
00154 }
00155 
00161 static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
00162     si->first_field = AV_NOPTS_VALUE;
00163     si->last_field = AV_NOPTS_VALUE;
00164     while (*len >= 2) {
00165         GXFMatTag tag = avio_r8(pb);
00166         int tlen = avio_r8(pb);
00167         *len -= 2;
00168         if (tlen > *len)
00169             return;
00170         *len -= tlen;
00171         if (tlen == 4) {
00172             uint32_t value = avio_rb32(pb);
00173             if (tag == MAT_FIRST_FIELD)
00174                 si->first_field = value;
00175             else if (tag == MAT_LAST_FIELD)
00176                 si->last_field = value;
00177         } else
00178             avio_skip(pb, tlen);
00179     }
00180 }
00181 
00187 static AVRational fps_tag2avr(int32_t fps) {
00188     extern const AVRational avpriv_frame_rate_tab[];
00189     if (fps < 1 || fps > 9) fps = 9;
00190     return avpriv_frame_rate_tab[9 - fps]; // values have opposite order
00191 }
00192 
00198 static AVRational fps_umf2avr(uint32_t flags) {
00199     static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
00200         {25, 1}, {30000, 1001}};
00201     int idx =  av_log2((flags & 0x7c0) >> 6);
00202     return map[idx];
00203 }
00204 
00210 static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
00211     si->frames_per_second = (AVRational){0, 0};
00212     si->fields_per_frame = 0;
00213     while (*len >= 2) {
00214         GXFTrackTag tag = avio_r8(pb);
00215         int tlen = avio_r8(pb);
00216         *len -= 2;
00217         if (tlen > *len)
00218             return;
00219         *len -= tlen;
00220         if (tlen == 4) {
00221             uint32_t value = avio_rb32(pb);
00222             if (tag == TRACK_FPS)
00223                 si->frames_per_second = fps_tag2avr(value);
00224             else if (tag == TRACK_FPF && (value == 1 || value == 2))
00225                 si->fields_per_frame = value;
00226         } else
00227             avio_skip(pb, tlen);
00228     }
00229 }
00230 
00234 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
00235     AVIOContext *pb = s->pb;
00236     AVStream *st = s->streams[0];
00237     uint32_t fields_per_map = avio_rl32(pb);
00238     uint32_t map_cnt = avio_rl32(pb);
00239     int i;
00240     pkt_len -= 8;
00241     if (s->flags & AVFMT_FLAG_IGNIDX) {
00242         avio_skip(pb, pkt_len);
00243         return;
00244     }
00245     if (map_cnt > 1000) {
00246         av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
00247         map_cnt = 1000;
00248     }
00249     if (pkt_len < 4 * map_cnt) {
00250         av_log(s, AV_LOG_ERROR, "invalid index length\n");
00251         avio_skip(pb, pkt_len);
00252         return;
00253     }
00254     pkt_len -= 4 * map_cnt;
00255     av_add_index_entry(st, 0, 0, 0, 0, 0);
00256     for (i = 0; i < map_cnt; i++)
00257         av_add_index_entry(st, (uint64_t)avio_rl32(pb) * 1024,
00258                            i * (uint64_t)fields_per_map + 1, 0, 0, 0);
00259     avio_skip(pb, pkt_len);
00260 }
00261 
00262 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
00263     AVIOContext *pb = s->pb;
00264     GXFPktType pkt_type;
00265     int map_len;
00266     int len;
00267     AVRational main_timebase = {0, 0};
00268     struct gxf_stream_info *si = s->priv_data;
00269     int i;
00270     if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
00271         av_log(s, AV_LOG_ERROR, "map packet not found\n");
00272         return 0;
00273     }
00274     map_len -= 2;
00275     if (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) {
00276         av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
00277         return 0;
00278     }
00279     map_len -= 2;
00280     len = avio_rb16(pb); // length of material data section
00281     if (len > map_len) {
00282         av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
00283         return 0;
00284     }
00285     map_len -= len;
00286     gxf_material_tags(pb, &len, si);
00287     avio_skip(pb, len);
00288     map_len -= 2;
00289     len = avio_rb16(pb); // length of track description
00290     if (len > map_len) {
00291         av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
00292         return 0;
00293     }
00294     map_len -= len;
00295     while (len > 0) {
00296         int track_type, track_id, track_len;
00297         AVStream *st;
00298         int idx;
00299         len -= 4;
00300         track_type = avio_r8(pb);
00301         track_id = avio_r8(pb);
00302         track_len = avio_rb16(pb);
00303         len -= track_len;
00304         gxf_track_tags(pb, &track_len, si);
00305         avio_skip(pb, track_len);
00306         if (!(track_type & 0x80)) {
00307            av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
00308            continue;
00309         }
00310         track_type &= 0x7f;
00311         if ((track_id & 0xc0) != 0xc0) {
00312            av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
00313            continue;
00314         }
00315         track_id &= 0x3f;
00316         idx = get_sindex(s, track_id, track_type);
00317         if (idx < 0) continue;
00318         st = s->streams[idx];
00319         if (!main_timebase.num || !main_timebase.den) {
00320             main_timebase.num = si->frames_per_second.den;
00321             main_timebase.den = si->frames_per_second.num * 2;
00322         }
00323         st->start_time = si->first_field;
00324         if (si->first_field != AV_NOPTS_VALUE && si->last_field != AV_NOPTS_VALUE)
00325             st->duration = si->last_field - si->first_field;
00326     }
00327     if (len < 0)
00328         av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
00329     if (map_len)
00330         avio_skip(pb, map_len);
00331     if (!parse_packet_header(pb, &pkt_type, &len)) {
00332         av_log(s, AV_LOG_ERROR, "sync lost in header\n");
00333         return -1;
00334     }
00335     if (pkt_type == PKT_FLT) {
00336         gxf_read_index(s, len);
00337         if (!parse_packet_header(pb, &pkt_type, &len)) {
00338             av_log(s, AV_LOG_ERROR, "sync lost in header\n");
00339             return -1;
00340         }
00341     }
00342     if (pkt_type == PKT_UMF) {
00343         if (len >= 0x39) {
00344             AVRational fps;
00345             len -= 0x39;
00346             avio_skip(pb, 5); // preamble
00347             avio_skip(pb, 0x30); // payload description
00348             fps = fps_umf2avr(avio_rl32(pb));
00349             if (!main_timebase.num || !main_timebase.den) {
00350                 // this may not always be correct, but simply the best we can get
00351                 main_timebase.num = fps.den;
00352                 main_timebase.den = fps.num * 2;
00353             }
00354         } else
00355             av_log(s, AV_LOG_INFO, "UMF packet too short\n");
00356     } else
00357         av_log(s, AV_LOG_INFO, "UMF packet missing\n");
00358     avio_skip(pb, len);
00359     // set a fallback value, 60000/1001 is specified for audio-only files
00360     // so use that regardless of why we do not know the video frame rate.
00361     if (!main_timebase.num || !main_timebase.den)
00362         main_timebase = (AVRational){1001, 60000};
00363     for (i = 0; i < s->nb_streams; i++) {
00364         AVStream *st = s->streams[i];
00365         avpriv_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
00366     }
00367     return 0;
00368 }
00369 
00370 #define READ_ONE() \
00371     { \
00372         if (!max_interval-- || pb->eof_reached) \
00373             goto out; \
00374         tmp = tmp << 8 | avio_r8(pb); \
00375     }
00376 
00384 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
00385     uint32_t tmp;
00386     uint64_t last_pos;
00387     uint64_t last_found_pos = 0;
00388     int cur_track;
00389     int64_t cur_timestamp = AV_NOPTS_VALUE;
00390     int len;
00391     AVIOContext *pb = s->pb;
00392     GXFPktType type;
00393     tmp = avio_rb32(pb);
00394 start:
00395     while (tmp)
00396         READ_ONE();
00397     READ_ONE();
00398     if (tmp != 1)
00399         goto start;
00400     last_pos = avio_tell(pb);
00401     if (avio_seek(pb, -5, SEEK_CUR) < 0)
00402         goto out;
00403     if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
00404         if (avio_seek(pb, last_pos, SEEK_SET) < 0)
00405             goto out;
00406         goto start;
00407     }
00408     avio_r8(pb);
00409     cur_track = avio_r8(pb);
00410     cur_timestamp = avio_rb32(pb);
00411     last_found_pos = avio_tell(pb) - 16 - 6;
00412     if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
00413         if (avio_seek(pb, last_pos, SEEK_SET) >= 0)
00414             goto start;
00415     }
00416 out:
00417     if (last_found_pos)
00418         avio_seek(pb, last_found_pos, SEEK_SET);
00419     return cur_timestamp;
00420 }
00421 
00422 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
00423     AVIOContext *pb = s->pb;
00424     GXFPktType pkt_type;
00425     int pkt_len;
00426     struct gxf_stream_info *si = s->priv_data;
00427 
00428     while (!pb->eof_reached) {
00429         AVStream *st;
00430         int track_type, track_id, ret;
00431         int field_nr, field_info, skip = 0;
00432         int stream_index;
00433         if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
00434             if (!pb->eof_reached)
00435                 av_log(s, AV_LOG_ERROR, "sync lost\n");
00436             return -1;
00437         }
00438         if (pkt_type == PKT_FLT) {
00439             gxf_read_index(s, pkt_len);
00440             continue;
00441         }
00442         if (pkt_type != PKT_MEDIA) {
00443             avio_skip(pb, pkt_len);
00444             continue;
00445         }
00446         if (pkt_len < 16) {
00447             av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
00448             continue;
00449         }
00450         pkt_len -= 16;
00451         track_type = avio_r8(pb);
00452         track_id = avio_r8(pb);
00453         stream_index = get_sindex(s, track_id, track_type);
00454         if (stream_index < 0)
00455             return stream_index;
00456         st = s->streams[stream_index];
00457         field_nr = avio_rb32(pb);
00458         field_info = avio_rb32(pb);
00459         avio_rb32(pb); // "timeline" field number
00460         avio_r8(pb); // flags
00461         avio_r8(pb); // reserved
00462         if (st->codec->codec_id == CODEC_ID_PCM_S24LE ||
00463             st->codec->codec_id == CODEC_ID_PCM_S16LE) {
00464             int first = field_info >> 16;
00465             int last  = field_info & 0xffff; // last is exclusive
00466             int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
00467             if (first <= last && last*bps <= pkt_len) {
00468                 avio_skip(pb, first*bps);
00469                 skip = pkt_len - last*bps;
00470                 pkt_len = (last-first)*bps;
00471             } else
00472                 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
00473         }
00474         ret = av_get_packet(pb, pkt, pkt_len);
00475         if (skip)
00476             avio_skip(pb, skip);
00477         pkt->stream_index = stream_index;
00478         pkt->dts = field_nr;
00479 
00480         //set duration manually for DV or else lavf misdetects the frame rate
00481         if (st->codec->codec_id == CODEC_ID_DVVIDEO)
00482             pkt->duration = si->fields_per_frame;
00483 
00484         return ret;
00485     }
00486     return AVERROR(EIO);
00487 }
00488 
00489 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
00490     int res = 0;
00491     uint64_t pos;
00492     uint64_t maxlen = 100 * 1024 * 1024;
00493     AVStream *st = s->streams[0];
00494     int64_t start_time = s->streams[stream_index]->start_time;
00495     int64_t found;
00496     int idx;
00497     if (timestamp < start_time) timestamp = start_time;
00498     idx = av_index_search_timestamp(st, timestamp - start_time,
00499                                     AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
00500     if (idx < 0)
00501         return -1;
00502     pos = st->index_entries[idx].pos;
00503     if (idx < st->nb_index_entries - 2)
00504         maxlen = st->index_entries[idx + 2].pos - pos;
00505     maxlen = FFMAX(maxlen, 200 * 1024);
00506     res = avio_seek(s->pb, pos, SEEK_SET);
00507     if (res < 0)
00508         return res;
00509     found = gxf_resync_media(s, maxlen, -1, timestamp);
00510     if (FFABS(found - timestamp) > 4)
00511         return -1;
00512     return 0;
00513 }
00514 
00515 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
00516                                   int64_t *pos, int64_t pos_limit) {
00517     AVIOContext *pb = s->pb;
00518     int64_t res;
00519     if (avio_seek(pb, *pos, SEEK_SET) < 0)
00520         return AV_NOPTS_VALUE;
00521     res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
00522     *pos = avio_tell(pb);
00523     return res;
00524 }
00525 
00526 AVInputFormat ff_gxf_demuxer = {
00527     .name           = "gxf",
00528     .long_name      = NULL_IF_CONFIG_SMALL("GXF format"),
00529     .priv_data_size = sizeof(struct gxf_stream_info),
00530     .read_probe     = gxf_probe,
00531     .read_header    = gxf_header,
00532     .read_packet    = gxf_packet,
00533     .read_seek      = gxf_seek,
00534     .read_timestamp = gxf_read_timestamp,
00535 };
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