FFmpeg: libavformat/gxf.c Source File

00001 /*
00002  * GXF demuxer.
00003  * Copyright (c) 2006 Reimar Doeffinger
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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/channel_layout.h"
00023 #include "libavutil/common.h"
00024 #include "avformat.h"
00025 #include "internal.h"
00026 #include "gxf.h"
00027 #include "libavcodec/mpeg12data.h"
00028 
00029 struct gxf_stream_info {
00030     int64_t first_field;
00031     int64_t last_field;
00032     AVRational frames_per_second;
00033     int32_t fields_per_frame;
00034     int64_t track_aux_data;
00035 };
00036 
00040 static int add_timecode_metadata(AVDictionary **pm, const char *key, uint32_t timecode, int fields_per_frame)
00041 {
00042    char tmp[128];
00043    int field  = timecode & 0xff;
00044    int frame  = fields_per_frame ? field / fields_per_frame : field;
00045    int second = (timecode >>  8) & 0xff;
00046    int minute = (timecode >> 16) & 0xff;
00047    int hour   = (timecode >> 24) & 0x1f;
00048    int drop   = (timecode >> 29) & 1;
00049    // bit 30: color_frame, unused
00050    // ignore invalid time code
00051    if (timecode >> 31)
00052        return 0;
00053    snprintf(tmp, sizeof(tmp), "%02d:%02d:%02d%c%02d",
00054        hour, minute, second, drop ? ';' : ':', frame);
00055    return av_dict_set(pm, key, tmp, 0);
00056 }
00057 
00065 static int parse_packet_header(AVIOContext *pb, GXFPktType *type, int *length) {
00066     if (avio_rb32(pb))
00067         return 0;
00068     if (avio_r8(pb) != 1)
00069         return 0;
00070     *type = avio_r8(pb);
00071     *length = avio_rb32(pb);
00072     if ((*length >> 24) || *length < 16)
00073         return 0;
00074     *length -= 16;
00075     if (avio_rb32(pb))
00076         return 0;
00077     if (avio_r8(pb) != 0xe1)
00078         return 0;
00079     if (avio_r8(pb) != 0xe2)
00080         return 0;
00081     return 1;
00082 }
00083 
00087 static int gxf_probe(AVProbeData *p) {
00088     static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
00089     static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
00090     if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
00091         !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
00092         return AVPROBE_SCORE_MAX;
00093     return 0;
00094 }
00095 
00102 static int get_sindex(AVFormatContext *s, int id, int format) {
00103     int i;
00104     AVStream *st = NULL;
00105     i = ff_find_stream_index(s, id);
00106     if (i >= 0)
00107         return i;
00108     st = avformat_new_stream(s, NULL);
00109     if (!st)
00110         return AVERROR(ENOMEM);
00111     st->id = id;
00112     switch (format) {
00113         case 3:
00114         case 4:
00115             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00116             st->codec->codec_id = AV_CODEC_ID_MJPEG;
00117             break;
00118         case 13:
00119         case 15:
00120             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00121             st->codec->codec_id = AV_CODEC_ID_DVVIDEO;
00122             break;
00123         case 14:
00124         case 16:
00125             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00126             st->codec->codec_id = AV_CODEC_ID_DVVIDEO;
00127             break;
00128         case 11:
00129         case 12:
00130         case 20:
00131             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00132             st->codec->codec_id = AV_CODEC_ID_MPEG2VIDEO;
00133             st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
00134             break;
00135         case 22:
00136         case 23:
00137             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00138             st->codec->codec_id = AV_CODEC_ID_MPEG1VIDEO;
00139             st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
00140             break;
00141         case 9:
00142             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00143             st->codec->codec_id = AV_CODEC_ID_PCM_S24LE;
00144             st->codec->channels = 1;
00145             st->codec->channel_layout = AV_CH_LAYOUT_MONO;
00146             st->codec->sample_rate = 48000;
00147             st->codec->bit_rate = 3 * 1 * 48000 * 8;
00148             st->codec->block_align = 3 * 1;
00149             st->codec->bits_per_coded_sample = 24;
00150             break;
00151         case 10:
00152             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00153             st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
00154             st->codec->channels = 1;
00155             st->codec->channel_layout = AV_CH_LAYOUT_MONO;
00156             st->codec->sample_rate = 48000;
00157             st->codec->bit_rate = 2 * 1 * 48000 * 8;
00158             st->codec->block_align = 2 * 1;
00159             st->codec->bits_per_coded_sample = 16;
00160             break;
00161         case 17:
00162             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00163             st->codec->codec_id = AV_CODEC_ID_AC3;
00164             st->codec->channels = 2;
00165             st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
00166             st->codec->sample_rate = 48000;
00167             break;
00168         // timecode tracks:
00169         case 7:
00170         case 8:
00171         case 24:
00172             st->codec->codec_type = AVMEDIA_TYPE_DATA;
00173             st->codec->codec_id = AV_CODEC_ID_NONE;
00174             break;
00175         default:
00176             st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
00177             st->codec->codec_id = AV_CODEC_ID_NONE;
00178             break;
00179     }
00180     return s->nb_streams - 1;
00181 }
00182 
00188 static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
00189     si->first_field = AV_NOPTS_VALUE;
00190     si->last_field = AV_NOPTS_VALUE;
00191     while (*len >= 2) {
00192         GXFMatTag tag = avio_r8(pb);
00193         int tlen = avio_r8(pb);
00194         *len -= 2;
00195         if (tlen > *len)
00196             return;
00197         *len -= tlen;
00198         if (tlen == 4) {
00199             uint32_t value = avio_rb32(pb);
00200             if (tag == MAT_FIRST_FIELD)
00201                 si->first_field = value;
00202             else if (tag == MAT_LAST_FIELD)
00203                 si->last_field = value;
00204         } else
00205             avio_skip(pb, tlen);
00206     }
00207 }
00208 
00209 static const AVRational frame_rate_tab[] = {
00210     {   60,    1},
00211     {60000, 1001},
00212     {   50,    1},
00213     {   30,    1},
00214     {30000, 1001},
00215     {   25,    1},
00216     {   24,    1},
00217     {24000, 1001},
00218     {    0,    0},
00219 };
00220 
00226 static AVRational fps_tag2avr(int32_t fps) {
00227     if (fps < 1 || fps > 9) fps = 9;
00228     return frame_rate_tab[fps - 1];
00229 }
00230 
00236 static AVRational fps_umf2avr(uint32_t flags) {
00237     static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
00238         {25, 1}, {30000, 1001}};
00239     int idx =  av_log2((flags & 0x7c0) >> 6);
00240     return map[idx];
00241 }
00242 
00248 static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
00249     si->frames_per_second = (AVRational){0, 0};
00250     si->fields_per_frame = 0;
00251     si->track_aux_data = 0x80000000;
00252     while (*len >= 2) {
00253         GXFTrackTag tag = avio_r8(pb);
00254         int tlen = avio_r8(pb);
00255         *len -= 2;
00256         if (tlen > *len)
00257             return;
00258         *len -= tlen;
00259         if (tlen == 4) {
00260             uint32_t value = avio_rb32(pb);
00261             if (tag == TRACK_FPS)
00262                 si->frames_per_second = fps_tag2avr(value);
00263             else if (tag == TRACK_FPF && (value == 1 || value == 2))
00264                 si->fields_per_frame = value;
00265         } else if (tlen == 8 && tag == TRACK_AUX)
00266             si->track_aux_data = avio_rl64(pb);
00267         else
00268             avio_skip(pb, tlen);
00269     }
00270 }
00271 
00275 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
00276     AVIOContext *pb = s->pb;
00277     AVStream *st;
00278     uint32_t fields_per_map = avio_rl32(pb);
00279     uint32_t map_cnt = avio_rl32(pb);
00280     int i;
00281     pkt_len -= 8;
00282     if ((s->flags & AVFMT_FLAG_IGNIDX) || !s->streams) {
00283         avio_skip(pb, pkt_len);
00284         return;
00285     }
00286     st = s->streams[0];
00287     if (map_cnt > 1000) {
00288         av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
00289         map_cnt = 1000;
00290     }
00291     if (pkt_len < 4 * map_cnt) {
00292         av_log(s, AV_LOG_ERROR, "invalid index length\n");
00293         avio_skip(pb, pkt_len);
00294         return;
00295     }
00296     pkt_len -= 4 * map_cnt;
00297     av_add_index_entry(st, 0, 0, 0, 0, 0);
00298     for (i = 0; i < map_cnt; i++)
00299         av_add_index_entry(st, (uint64_t)avio_rl32(pb) * 1024,
00300                            i * (uint64_t)fields_per_map + 1, 0, 0, 0);
00301     avio_skip(pb, pkt_len);
00302 }
00303 
00304 static int gxf_header(AVFormatContext *s) {
00305     AVIOContext *pb = s->pb;
00306     GXFPktType pkt_type;
00307     int map_len;
00308     int len;
00309     AVRational main_timebase = {0, 0};
00310     struct gxf_stream_info *si = s->priv_data;
00311     int i;
00312     if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
00313         av_log(s, AV_LOG_ERROR, "map packet not found\n");
00314         return 0;
00315     }
00316     map_len -= 2;
00317     if (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) {
00318         av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
00319         return 0;
00320     }
00321     map_len -= 2;
00322     len = avio_rb16(pb); // length of material data section
00323     if (len > map_len) {
00324         av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
00325         return 0;
00326     }
00327     map_len -= len;
00328     gxf_material_tags(pb, &len, si);
00329     avio_skip(pb, len);
00330     map_len -= 2;
00331     len = avio_rb16(pb); // length of track description
00332     if (len > map_len) {
00333         av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
00334         return 0;
00335     }
00336     map_len -= len;
00337     while (len > 0) {
00338         int track_type, track_id, track_len;
00339         AVStream *st;
00340         int idx;
00341         len -= 4;
00342         track_type = avio_r8(pb);
00343         track_id = avio_r8(pb);
00344         track_len = avio_rb16(pb);
00345         len -= track_len;
00346         if (!(track_type & 0x80)) {
00347            av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
00348            continue;
00349         }
00350         track_type &= 0x7f;
00351         if ((track_id & 0xc0) != 0xc0) {
00352            av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
00353            continue;
00354         }
00355         track_id &= 0x3f;
00356         gxf_track_tags(pb, &track_len, si);
00357         // check for timecode tracks
00358         if (track_type == 7 || track_type == 8 || track_type == 24) {
00359             add_timecode_metadata(&s->metadata, "timecode",
00360                                   si->track_aux_data & 0xffffffff,
00361                                   si->fields_per_frame);
00362 
00363         }
00364         avio_skip(pb, track_len);
00365 
00366         idx = get_sindex(s, track_id, track_type);
00367         if (idx < 0) continue;
00368         st = s->streams[idx];
00369         if (!main_timebase.num || !main_timebase.den) {
00370             main_timebase.num = si->frames_per_second.den;
00371             main_timebase.den = si->frames_per_second.num * 2;
00372         }
00373         st->start_time = si->first_field;
00374         if (si->first_field != AV_NOPTS_VALUE && si->last_field != AV_NOPTS_VALUE)
00375             st->duration = si->last_field - si->first_field;
00376     }
00377     if (len < 0)
00378         av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
00379     if (map_len)
00380         avio_skip(pb, map_len);
00381     if (!parse_packet_header(pb, &pkt_type, &len)) {
00382         av_log(s, AV_LOG_ERROR, "sync lost in header\n");
00383         return -1;
00384     }
00385     if (pkt_type == PKT_FLT) {
00386         gxf_read_index(s, len);
00387         if (!parse_packet_header(pb, &pkt_type, &len)) {
00388             av_log(s, AV_LOG_ERROR, "sync lost in header\n");
00389             return -1;
00390         }
00391     }
00392     if (pkt_type == PKT_UMF) {
00393         if (len >= 0x39) {
00394             AVRational fps;
00395             len -= 0x39;
00396             avio_skip(pb, 5); // preamble
00397             avio_skip(pb, 0x30); // payload description
00398             fps = fps_umf2avr(avio_rl32(pb));
00399             if (!main_timebase.num || !main_timebase.den) {
00400                 av_log(s, AV_LOG_WARNING, "No FPS track tag, using UMF fps tag."
00401                                           " This might give wrong results.\n");
00402                 // this may not always be correct, but simply the best we can get
00403                 main_timebase.num = fps.den;
00404                 main_timebase.den = fps.num * 2;
00405             }
00406 
00407             if (len >= 0x18) {
00408                 len -= 0x18;
00409                 avio_skip(pb, 0x10);
00410                 add_timecode_metadata(&s->metadata, "timecode_at_mark_in",
00411                                       avio_rl32(pb), si->fields_per_frame);
00412                 add_timecode_metadata(&s->metadata, "timecode_at_mark_out",
00413                                       avio_rl32(pb), si->fields_per_frame);
00414             }
00415         } else
00416             av_log(s, AV_LOG_INFO, "UMF packet too short\n");
00417     } else
00418         av_log(s, AV_LOG_INFO, "UMF packet missing\n");
00419     avio_skip(pb, len);
00420     // set a fallback value, 60000/1001 is specified for audio-only files
00421     // so use that regardless of why we do not know the video frame rate.
00422     if (!main_timebase.num || !main_timebase.den)
00423         main_timebase = (AVRational){1001, 60000};
00424     for (i = 0; i < s->nb_streams; i++) {
00425         AVStream *st = s->streams[i];
00426         avpriv_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
00427     }
00428     return 0;
00429 }
00430 
00431 #define READ_ONE() \
00432     { \
00433         if (!max_interval-- || url_feof(pb)) \
00434             goto out; \
00435         tmp = tmp << 8 | avio_r8(pb); \
00436     }
00437 
00445 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
00446     uint32_t tmp;
00447     uint64_t last_pos;
00448     uint64_t last_found_pos = 0;
00449     int cur_track;
00450     int64_t cur_timestamp = AV_NOPTS_VALUE;
00451     int len;
00452     AVIOContext *pb = s->pb;
00453     GXFPktType type;
00454     tmp = avio_rb32(pb);
00455 start:
00456     while (tmp)
00457         READ_ONE();
00458     READ_ONE();
00459     if (tmp != 1)
00460         goto start;
00461     last_pos = avio_tell(pb);
00462     if (avio_seek(pb, -5, SEEK_CUR) < 0)
00463         goto out;
00464     if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
00465         if (avio_seek(pb, last_pos, SEEK_SET) < 0)
00466             goto out;
00467         goto start;
00468     }
00469     avio_r8(pb);
00470     cur_track = avio_r8(pb);
00471     cur_timestamp = avio_rb32(pb);
00472     last_found_pos = avio_tell(pb) - 16 - 6;
00473     if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
00474         if (avio_seek(pb, last_pos, SEEK_SET) >= 0)
00475             goto start;
00476     }
00477 out:
00478     if (last_found_pos)
00479         avio_seek(pb, last_found_pos, SEEK_SET);
00480     return cur_timestamp;
00481 }
00482 
00483 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
00484     AVIOContext *pb = s->pb;
00485     GXFPktType pkt_type;
00486     int pkt_len;
00487     struct gxf_stream_info *si = s->priv_data;
00488 
00489     while (!pb->eof_reached) {
00490         AVStream *st;
00491         int track_type, track_id, ret;
00492         int field_nr, field_info, skip = 0;
00493         int stream_index;
00494         if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
00495             if (!url_feof(pb))
00496                 av_log(s, AV_LOG_ERROR, "sync lost\n");
00497             return -1;
00498         }
00499         if (pkt_type == PKT_FLT) {
00500             gxf_read_index(s, pkt_len);
00501             continue;
00502         }
00503         if (pkt_type != PKT_MEDIA) {
00504             avio_skip(pb, pkt_len);
00505             continue;
00506         }
00507         if (pkt_len < 16) {
00508             av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
00509             continue;
00510         }
00511         pkt_len -= 16;
00512         track_type = avio_r8(pb);
00513         track_id = avio_r8(pb);
00514         stream_index = get_sindex(s, track_id, track_type);
00515         if (stream_index < 0)
00516             return stream_index;
00517         st = s->streams[stream_index];
00518         field_nr = avio_rb32(pb);
00519         field_info = avio_rb32(pb);
00520         avio_rb32(pb); // "timeline" field number
00521         avio_r8(pb); // flags
00522         avio_r8(pb); // reserved
00523         if (st->codec->codec_id == AV_CODEC_ID_PCM_S24LE ||
00524             st->codec->codec_id == AV_CODEC_ID_PCM_S16LE) {
00525             int first = field_info >> 16;
00526             int last  = field_info & 0xffff; // last is exclusive
00527             int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
00528             if (first <= last && last*bps <= pkt_len) {
00529                 avio_skip(pb, first*bps);
00530                 skip = pkt_len - last*bps;
00531                 pkt_len = (last-first)*bps;
00532             } else
00533                 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
00534         }
00535         ret = av_get_packet(pb, pkt, pkt_len);
00536         if (skip)
00537             avio_skip(pb, skip);
00538         pkt->stream_index = stream_index;
00539         pkt->dts = field_nr;
00540 
00541         //set duration manually for DV or else lavf misdetects the frame rate
00542         if (st->codec->codec_id == AV_CODEC_ID_DVVIDEO)
00543             pkt->duration = si->fields_per_frame;
00544 
00545         return ret;
00546     }
00547     return AVERROR_EOF;
00548 }
00549 
00550 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
00551     int res = 0;
00552     uint64_t pos;
00553     uint64_t maxlen = 100 * 1024 * 1024;
00554     AVStream *st = s->streams[0];
00555     int64_t start_time = s->streams[stream_index]->start_time;
00556     int64_t found;
00557     int idx;
00558     if (timestamp < start_time) timestamp = start_time;
00559     idx = av_index_search_timestamp(st, timestamp - start_time,
00560                                     AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
00561     if (idx < 0)
00562         return -1;
00563     pos = st->index_entries[idx].pos;
00564     if (idx < st->nb_index_entries - 2)
00565         maxlen = st->index_entries[idx + 2].pos - pos;
00566     maxlen = FFMAX(maxlen, 200 * 1024);
00567     res = avio_seek(s->pb, pos, SEEK_SET);
00568     if (res < 0)
00569         return res;
00570     found = gxf_resync_media(s, maxlen, -1, timestamp);
00571     if (FFABS(found - timestamp) > 4)
00572         return -1;
00573     return 0;
00574 }
00575 
00576 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
00577                                   int64_t *pos, int64_t pos_limit) {
00578     AVIOContext *pb = s->pb;
00579     int64_t res;
00580     if (avio_seek(pb, *pos, SEEK_SET) < 0)
00581         return AV_NOPTS_VALUE;
00582     res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
00583     *pos = avio_tell(pb);
00584     return res;
00585 }
00586 
00587 AVInputFormat ff_gxf_demuxer = {
00588     .name           = "gxf",
00589     .long_name      = NULL_IF_CONFIG_SMALL("GXF (General eXchange Format)"),
00590     .priv_data_size = sizeof(struct gxf_stream_info),
00591     .read_probe     = gxf_probe,
00592     .read_header    = gxf_header,
00593     .read_packet    = gxf_packet,
00594     .read_seek      = gxf_seek,
00595     .read_timestamp = gxf_read_timestamp,
00596 };