3 * Copyright (c) 2006 Reimar Doeffinger.
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/common.h"
29 AVRational frames_per_second;
30 int32_t fields_per_frame;
34 * \brief parses a packet header, extracting type and length
35 * \param pb ByteIOContext to read header from
36 * \param type detected packet type is stored here
37 * \param length detected packet length, excluding header is stored here
38 * \return 0 if header not found or contains invalid data, 1 otherwise
40 static int parse_packet_header(ByteIOContext *pb, pkt_type_t *type, int *length) {
43 if (get_byte(pb) != 1)
46 *length = get_be32(pb);
47 if ((*length >> 24) || *length < 16)
52 if (get_byte(pb) != 0xe1)
54 if (get_byte(pb) != 0xe2)
60 * \brief check if file starts with a PKT_MAP header
62 static int gxf_probe(AVProbeData *p) {
63 static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
64 static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
65 if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
66 !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
67 return AVPROBE_SCORE_MAX;
72 * \brief gets the stream index for the track with the specified id, creates new
74 * \param stream id of stream to find / add
75 * \param format stream format identifier
77 static int get_sindex(AVFormatContext *s, int id, int format) {
80 for (i = 0; i < s->nb_streams; i++) {
81 if (s->streams[i]->id == id)
84 st = av_new_stream(s, id);
88 st->codec->codec_type = CODEC_TYPE_VIDEO;
89 st->codec->codec_id = CODEC_ID_MJPEG;
93 st->codec->codec_type = CODEC_TYPE_VIDEO;
94 st->codec->codec_id = CODEC_ID_DVVIDEO;
98 st->codec->codec_type = CODEC_TYPE_VIDEO;
99 st->codec->codec_id = CODEC_ID_DVVIDEO;
104 st->codec->codec_type = CODEC_TYPE_VIDEO;
105 st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
106 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
110 st->codec->codec_type = CODEC_TYPE_VIDEO;
111 st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
112 st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
115 st->codec->codec_type = CODEC_TYPE_AUDIO;
116 st->codec->codec_id = CODEC_ID_PCM_S24LE;
117 st->codec->channels = 1;
118 st->codec->sample_rate = 48000;
119 st->codec->bit_rate = 3 * 1 * 48000 * 8;
120 st->codec->block_align = 3 * 1;
121 st->codec->bits_per_sample = 24;
124 st->codec->codec_type = CODEC_TYPE_AUDIO;
125 st->codec->codec_id = CODEC_ID_PCM_S16LE;
126 st->codec->channels = 1;
127 st->codec->sample_rate = 48000;
128 st->codec->bit_rate = 2 * 1 * 48000 * 8;
129 st->codec->block_align = 2 * 1;
130 st->codec->bits_per_sample = 16;
133 st->codec->codec_type = CODEC_TYPE_AUDIO;
134 st->codec->codec_id = CODEC_ID_AC3;
135 st->codec->channels = 2;
136 st->codec->sample_rate = 48000;
142 st->codec->codec_type = CODEC_TYPE_DATA;
143 st->codec->codec_id = CODEC_ID_NONE;
146 st->codec->codec_type = CODEC_TYPE_UNKNOWN;
147 st->codec->codec_id = CODEC_ID_NONE;
150 return s->nb_streams - 1;
154 * \brief filters out interesting tags from material information.
155 * \param len length of tag section, will be adjusted to contain remaining bytes
156 * \param si struct to store collected information into
158 static void gxf_material_tags(ByteIOContext *pb, int *len, st_info_t *si) {
159 si->first_field = AV_NOPTS_VALUE;
160 si->last_field = AV_NOPTS_VALUE;
162 mat_tag_t tag = get_byte(pb);
163 int tlen = get_byte(pb);
169 uint32_t value = get_be32(pb);
170 if (tag == MAT_FIRST_FIELD)
171 si->first_field = value;
172 else if (tag == MAT_LAST_FIELD)
173 si->last_field = value;
180 * \brief convert fps tag value to AVRational fps
181 * \param fps fps value from tag
182 * \return fps as AVRational, or 0 / 0 if unknown
184 static AVRational fps_tag2avr(int32_t fps) {
185 extern const AVRational ff_frame_rate_tab[];
186 if (fps < 1 || fps > 9) fps = 9;
187 return ff_frame_rate_tab[9 - fps]; // values have opposite order
191 * \brief convert UMF attributes flags to AVRational fps
192 * \param fps fps value from flags
193 * \return fps as AVRational, or 0 / 0 if unknown
195 static AVRational fps_umf2avr(uint32_t flags) {
196 static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
197 {25, 1}, {30000, 1001}};
198 int idx = av_log2((flags & 0x7c0) >> 6);
203 * \brief filters out interesting tags from track information.
204 * \param len length of tag section, will be adjusted to contain remaining bytes
205 * \param si struct to store collected information into
207 static void gxf_track_tags(ByteIOContext *pb, int *len, st_info_t *si) {
208 si->frames_per_second = (AVRational){0, 0};
209 si->fields_per_frame = 0;
211 track_tag_t tag = get_byte(pb);
212 int tlen = get_byte(pb);
218 uint32_t value = get_be32(pb);
219 if (tag == TRACK_FPS)
220 si->frames_per_second = fps_tag2avr(value);
221 else if (tag == TRACK_FPF && (value == 1 || value == 2))
222 si->fields_per_frame = value;
229 * \brief read index from FLT packet into stream 0 av_index
231 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
232 ByteIOContext *pb = s->pb;
233 AVStream *st = s->streams[0];
234 uint32_t fields_per_map = get_le32(pb);
235 uint32_t map_cnt = get_le32(pb);
238 if (map_cnt > 1000) {
239 av_log(s, AV_LOG_ERROR, "GXF: too many index entries %u (%x)\n", map_cnt, map_cnt);
242 if (pkt_len < 4 * map_cnt) {
243 av_log(s, AV_LOG_ERROR, "GXF: invalid index length\n");
244 url_fskip(pb, pkt_len);
247 pkt_len -= 4 * map_cnt;
248 av_add_index_entry(st, 0, 0, 0, 0, 0);
249 for (i = 0; i < map_cnt; i++)
250 av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
251 i * (uint64_t)fields_per_map + 1, 0, 0, 0);
252 url_fskip(pb, pkt_len);
255 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
256 ByteIOContext *pb = s->pb;
260 AVRational main_timebase = {0, 0};
263 if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
264 av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n");
268 if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
269 av_log(s, AV_LOG_ERROR, "GXF: unknown version or invalid map preamble\n");
273 len = get_be16(pb); // length of material data section
275 av_log(s, AV_LOG_ERROR, "GXF: material data longer than map data\n");
279 gxf_material_tags(pb, &len, &si);
282 len = get_be16(pb); // length of track description
284 av_log(s, AV_LOG_ERROR, "GXF: track description longer than map data\n");
289 int track_type, track_id, track_len;
293 track_type = get_byte(pb);
294 track_id = get_byte(pb);
295 track_len = get_be16(pb);
297 gxf_track_tags(pb, &track_len, &si);
298 url_fskip(pb, track_len);
299 if (!(track_type & 0x80)) {
300 av_log(s, AV_LOG_ERROR, "GXF: invalid track type %x\n", track_type);
304 if ((track_id & 0xc0) != 0xc0) {
305 av_log(s, AV_LOG_ERROR, "GXF: invalid track id %x\n", track_id);
309 idx = get_sindex(s, track_id, track_type);
310 if (idx < 0) continue;
311 st = s->streams[idx];
312 if (!main_timebase.num || !main_timebase.den) {
313 main_timebase.num = si.frames_per_second.den;
314 main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
316 st->start_time = si.first_field;
317 if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
318 st->duration = si.last_field - si.first_field;
321 av_log(s, AV_LOG_ERROR, "GXF: invalid track description length specified\n");
323 url_fskip(pb, map_len);
324 if (!parse_packet_header(pb, &pkt_type, &len)) {
325 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
328 if (pkt_type == PKT_FLT) {
329 gxf_read_index(s, len);
330 if (!parse_packet_header(pb, &pkt_type, &len)) {
331 av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
335 if (pkt_type == PKT_UMF) {
339 url_fskip(pb, 5); // preamble
340 url_fskip(pb, 0x30); // payload description
341 fps = fps_umf2avr(get_le32(pb));
342 if (!main_timebase.num || !main_timebase.den) {
343 // this may not always be correct, but simply the best we can get
344 main_timebase.num = fps.den;
345 main_timebase.den = fps.num;
348 av_log(s, AV_LOG_INFO, "GXF: UMF packet too short\n");
350 av_log(s, AV_LOG_INFO, "GXF: UMF packet missing\n");
352 if (!main_timebase.num || !main_timebase.den)
353 main_timebase = (AVRational){1, 50}; // set some arbitrary fallback
354 for (i = 0; i < s->nb_streams; i++) {
355 AVStream *st = s->streams[i];
356 av_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
363 if (!max_interval-- || url_feof(pb)) \
365 tmp = tmp << 8 | get_byte(pb); \
369 * \brief resync the stream on the next media packet with specified properties
370 * \param max_interval how many bytes to search for matching packet at most
371 * \param track track id the media packet must belong to, -1 for any
372 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
373 * \return timestamp of packet found
375 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
378 uint64_t last_found_pos = 0;
380 int64_t cur_timestamp = AV_NOPTS_VALUE;
382 ByteIOContext *pb = s->pb;
391 last_pos = url_ftell(pb);
392 url_fseek(pb, -5, SEEK_CUR);
393 if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
394 url_fseek(pb, last_pos, SEEK_SET);
398 cur_track = get_byte(pb);
399 cur_timestamp = get_be32(pb);
400 last_found_pos = url_ftell(pb) - 16 - 6;
401 if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
402 url_fseek(pb, last_pos, SEEK_SET);
407 url_fseek(pb, last_found_pos, SEEK_SET);
408 return cur_timestamp;
411 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
412 ByteIOContext *pb = s->pb;
415 while (!url_feof(pb)) {
416 int track_type, track_id, ret;
418 if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
420 av_log(s, AV_LOG_ERROR, "GXF: sync lost\n");
423 if (pkt_type == PKT_FLT) {
424 gxf_read_index(s, pkt_len);
427 if (pkt_type != PKT_MEDIA) {
428 url_fskip(pb, pkt_len);
432 av_log(s, AV_LOG_ERROR, "GXF: invalid media packet length\n");
436 track_type = get_byte(pb);
437 track_id = get_byte(pb);
438 field_nr = get_be32(pb);
439 get_be32(pb); // field information
440 get_be32(pb); // "timeline" field number
441 get_byte(pb); // flags
442 get_byte(pb); // reserved
443 // NOTE: there is also data length information in the
444 // field information, it might be better to take this into account
446 ret = av_get_packet(pb, pkt, pkt_len);
447 pkt->stream_index = get_sindex(s, track_id, track_type);
454 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
456 uint64_t maxlen = 100 * 1024 * 1024;
457 AVStream *st = s->streams[0];
458 int64_t start_time = s->streams[stream_index]->start_time;
461 if (timestamp < start_time) timestamp = start_time;
462 idx = av_index_search_timestamp(st, timestamp - start_time,
463 AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
466 pos = st->index_entries[idx].pos;
467 if (idx < st->nb_index_entries - 2)
468 maxlen = st->index_entries[idx + 2].pos - pos;
469 maxlen = FFMAX(maxlen, 200 * 1024);
470 url_fseek(s->pb, pos, SEEK_SET);
471 found = gxf_resync_media(s, maxlen, -1, timestamp);
472 if (FFABS(found - timestamp) > 4)
477 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
478 int64_t *pos, int64_t pos_limit) {
479 ByteIOContext *pb = s->pb;
481 url_fseek(pb, *pos, SEEK_SET);
482 res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
483 *pos = url_ftell(pb);
487 AVInputFormat gxf_demuxer = {