| /* |
| * GXF demuxer. |
| * Copyright (c) 2006 Reimar Doeffinger |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "libavutil/common.h" |
| #include "avformat.h" |
| #include "gxf.h" |
| |
| struct gxf_stream_info { |
| int64_t first_field; |
| int64_t last_field; |
| AVRational frames_per_second; |
| int32_t fields_per_frame; |
| }; |
| |
| /** |
| * \brief parses a packet header, extracting type and length |
| * \param pb ByteIOContext to read header from |
| * \param type detected packet type is stored here |
| * \param length detected packet length, excluding header is stored here |
| * \return 0 if header not found or contains invalid data, 1 otherwise |
| */ |
| static int parse_packet_header(ByteIOContext *pb, GXFPktType *type, int *length) { |
| if (get_be32(pb)) |
| return 0; |
| if (get_byte(pb) != 1) |
| return 0; |
| *type = get_byte(pb); |
| *length = get_be32(pb); |
| if ((*length >> 24) || *length < 16) |
| return 0; |
| *length -= 16; |
| if (get_be32(pb)) |
| return 0; |
| if (get_byte(pb) != 0xe1) |
| return 0; |
| if (get_byte(pb) != 0xe2) |
| return 0; |
| return 1; |
| } |
| |
| /** |
| * \brief check if file starts with a PKT_MAP header |
| */ |
| static int gxf_probe(AVProbeData *p) { |
| static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet |
| static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2}; |
| if (!memcmp(p->buf, startcode, sizeof(startcode)) && |
| !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode))) |
| return AVPROBE_SCORE_MAX; |
| return 0; |
| } |
| |
| /** |
| * \brief gets the stream index for the track with the specified id, creates new |
| * stream if not found |
| * \param stream id of stream to find / add |
| * \param format stream format identifier |
| */ |
| static int get_sindex(AVFormatContext *s, int id, int format) { |
| int i; |
| AVStream *st = NULL; |
| for (i = 0; i < s->nb_streams; i++) { |
| if (s->streams[i]->id == id) |
| return i; |
| } |
| st = av_new_stream(s, id); |
| if (!st) |
| return AVERROR(ENOMEM); |
| switch (format) { |
| case 3: |
| case 4: |
| st->codec->codec_type = CODEC_TYPE_VIDEO; |
| st->codec->codec_id = CODEC_ID_MJPEG; |
| break; |
| case 13: |
| case 15: |
| st->codec->codec_type = CODEC_TYPE_VIDEO; |
| st->codec->codec_id = CODEC_ID_DVVIDEO; |
| break; |
| case 14: |
| case 16: |
| st->codec->codec_type = CODEC_TYPE_VIDEO; |
| st->codec->codec_id = CODEC_ID_DVVIDEO; |
| break; |
| case 11: |
| case 12: |
| case 20: |
| st->codec->codec_type = CODEC_TYPE_VIDEO; |
| st->codec->codec_id = CODEC_ID_MPEG2VIDEO; |
| st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc. |
| break; |
| case 22: |
| case 23: |
| st->codec->codec_type = CODEC_TYPE_VIDEO; |
| st->codec->codec_id = CODEC_ID_MPEG1VIDEO; |
| st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc. |
| break; |
| case 9: |
| st->codec->codec_type = CODEC_TYPE_AUDIO; |
| st->codec->codec_id = CODEC_ID_PCM_S24LE; |
| st->codec->channels = 1; |
| st->codec->sample_rate = 48000; |
| st->codec->bit_rate = 3 * 1 * 48000 * 8; |
| st->codec->block_align = 3 * 1; |
| st->codec->bits_per_coded_sample = 24; |
| break; |
| case 10: |
| st->codec->codec_type = CODEC_TYPE_AUDIO; |
| st->codec->codec_id = CODEC_ID_PCM_S16LE; |
| st->codec->channels = 1; |
| st->codec->sample_rate = 48000; |
| st->codec->bit_rate = 2 * 1 * 48000 * 8; |
| st->codec->block_align = 2 * 1; |
| st->codec->bits_per_coded_sample = 16; |
| break; |
| case 17: |
| st->codec->codec_type = CODEC_TYPE_AUDIO; |
| st->codec->codec_id = CODEC_ID_AC3; |
| st->codec->channels = 2; |
| st->codec->sample_rate = 48000; |
| break; |
| // timecode tracks: |
| case 7: |
| case 8: |
| case 24: |
| st->codec->codec_type = CODEC_TYPE_DATA; |
| st->codec->codec_id = CODEC_ID_NONE; |
| break; |
| default: |
| st->codec->codec_type = CODEC_TYPE_UNKNOWN; |
| st->codec->codec_id = CODEC_ID_NONE; |
| break; |
| } |
| return s->nb_streams - 1; |
| } |
| |
| /** |
| * \brief filters out interesting tags from material information. |
| * \param len length of tag section, will be adjusted to contain remaining bytes |
| * \param si struct to store collected information into |
| */ |
| static void gxf_material_tags(ByteIOContext *pb, int *len, struct gxf_stream_info *si) { |
| si->first_field = AV_NOPTS_VALUE; |
| si->last_field = AV_NOPTS_VALUE; |
| while (*len >= 2) { |
| GXFMatTag tag = get_byte(pb); |
| int tlen = get_byte(pb); |
| *len -= 2; |
| if (tlen > *len) |
| return; |
| *len -= tlen; |
| if (tlen == 4) { |
| uint32_t value = get_be32(pb); |
| if (tag == MAT_FIRST_FIELD) |
| si->first_field = value; |
| else if (tag == MAT_LAST_FIELD) |
| si->last_field = value; |
| } else |
| url_fskip(pb, tlen); |
| } |
| } |
| |
| /** |
| * \brief convert fps tag value to AVRational fps |
| * \param fps fps value from tag |
| * \return fps as AVRational, or 0 / 0 if unknown |
| */ |
| static AVRational fps_tag2avr(int32_t fps) { |
| extern const AVRational ff_frame_rate_tab[]; |
| if (fps < 1 || fps > 9) fps = 9; |
| return ff_frame_rate_tab[9 - fps]; // values have opposite order |
| } |
| |
| /** |
| * \brief convert UMF attributes flags to AVRational fps |
| * \param fps fps value from flags |
| * \return fps as AVRational, or 0 / 0 if unknown |
| */ |
| static AVRational fps_umf2avr(uint32_t flags) { |
| static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1}, |
| {25, 1}, {30000, 1001}}; |
| int idx = av_log2((flags & 0x7c0) >> 6); |
| return map[idx]; |
| } |
| |
| /** |
| * \brief filters out interesting tags from track information. |
| * \param len length of tag section, will be adjusted to contain remaining bytes |
| * \param si struct to store collected information into |
| */ |
| static void gxf_track_tags(ByteIOContext *pb, int *len, struct gxf_stream_info *si) { |
| si->frames_per_second = (AVRational){0, 0}; |
| si->fields_per_frame = 0; |
| while (*len >= 2) { |
| GXFTrackTag tag = get_byte(pb); |
| int tlen = get_byte(pb); |
| *len -= 2; |
| if (tlen > *len) |
| return; |
| *len -= tlen; |
| if (tlen == 4) { |
| uint32_t value = get_be32(pb); |
| if (tag == TRACK_FPS) |
| si->frames_per_second = fps_tag2avr(value); |
| else if (tag == TRACK_FPF && (value == 1 || value == 2)) |
| si->fields_per_frame = value; |
| } else |
| url_fskip(pb, tlen); |
| } |
| } |
| |
| /** |
| * \brief read index from FLT packet into stream 0 av_index |
| */ |
| static void gxf_read_index(AVFormatContext *s, int pkt_len) { |
| ByteIOContext *pb = s->pb; |
| AVStream *st = s->streams[0]; |
| uint32_t fields_per_map = get_le32(pb); |
| uint32_t map_cnt = get_le32(pb); |
| int i; |
| pkt_len -= 8; |
| if (map_cnt > 1000) { |
| av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt); |
| map_cnt = 1000; |
| } |
| if (pkt_len < 4 * map_cnt) { |
| av_log(s, AV_LOG_ERROR, "invalid index length\n"); |
| url_fskip(pb, pkt_len); |
| return; |
| } |
| pkt_len -= 4 * map_cnt; |
| av_add_index_entry(st, 0, 0, 0, 0, 0); |
| for (i = 0; i < map_cnt; i++) |
| av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024, |
| i * (uint64_t)fields_per_map + 1, 0, 0, 0); |
| url_fskip(pb, pkt_len); |
| } |
| |
| static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) { |
| ByteIOContext *pb = s->pb; |
| GXFPktType pkt_type; |
| int map_len; |
| int len; |
| AVRational main_timebase = {0, 0}; |
| struct gxf_stream_info si; |
| int i; |
| if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) { |
| av_log(s, AV_LOG_ERROR, "map packet not found\n"); |
| return 0; |
| } |
| map_len -= 2; |
| if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) { |
| av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n"); |
| return 0; |
| } |
| map_len -= 2; |
| len = get_be16(pb); // length of material data section |
| if (len > map_len) { |
| av_log(s, AV_LOG_ERROR, "material data longer than map data\n"); |
| return 0; |
| } |
| map_len -= len; |
| gxf_material_tags(pb, &len, &si); |
| url_fskip(pb, len); |
| map_len -= 2; |
| len = get_be16(pb); // length of track description |
| if (len > map_len) { |
| av_log(s, AV_LOG_ERROR, "track description longer than map data\n"); |
| return 0; |
| } |
| map_len -= len; |
| while (len > 0) { |
| int track_type, track_id, track_len; |
| AVStream *st; |
| int idx; |
| len -= 4; |
| track_type = get_byte(pb); |
| track_id = get_byte(pb); |
| track_len = get_be16(pb); |
| len -= track_len; |
| gxf_track_tags(pb, &track_len, &si); |
| url_fskip(pb, track_len); |
| if (!(track_type & 0x80)) { |
| av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type); |
| continue; |
| } |
| track_type &= 0x7f; |
| if ((track_id & 0xc0) != 0xc0) { |
| av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id); |
| continue; |
| } |
| track_id &= 0x3f; |
| idx = get_sindex(s, track_id, track_type); |
| if (idx < 0) continue; |
| st = s->streams[idx]; |
| if (!main_timebase.num || !main_timebase.den) { |
| main_timebase.num = si.frames_per_second.den; |
| main_timebase.den = si.frames_per_second.num * si.fields_per_frame; |
| } |
| st->start_time = si.first_field; |
| if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE) |
| st->duration = si.last_field - si.first_field; |
| } |
| if (len < 0) |
| av_log(s, AV_LOG_ERROR, "invalid track description length specified\n"); |
| if (map_len) |
| url_fskip(pb, map_len); |
| if (!parse_packet_header(pb, &pkt_type, &len)) { |
| av_log(s, AV_LOG_ERROR, "sync lost in header\n"); |
| return -1; |
| } |
| if (pkt_type == PKT_FLT) { |
| gxf_read_index(s, len); |
| if (!parse_packet_header(pb, &pkt_type, &len)) { |
| av_log(s, AV_LOG_ERROR, "sync lost in header\n"); |
| return -1; |
| } |
| } |
| if (pkt_type == PKT_UMF) { |
| if (len >= 0x39) { |
| AVRational fps; |
| len -= 0x39; |
| url_fskip(pb, 5); // preamble |
| url_fskip(pb, 0x30); // payload description |
| fps = fps_umf2avr(get_le32(pb)); |
| if (!main_timebase.num || !main_timebase.den) { |
| // this may not always be correct, but simply the best we can get |
| main_timebase.num = fps.den; |
| main_timebase.den = fps.num; |
| } |
| } else |
| av_log(s, AV_LOG_INFO, "UMF packet too short\n"); |
| } else |
| av_log(s, AV_LOG_INFO, "UMF packet missing\n"); |
| url_fskip(pb, len); |
| if (!main_timebase.num || !main_timebase.den) |
| main_timebase = (AVRational){1, 50}; // set some arbitrary fallback |
| for (i = 0; i < s->nb_streams; i++) { |
| AVStream *st = s->streams[i]; |
| av_set_pts_info(st, 32, main_timebase.num, main_timebase.den); |
| } |
| return 0; |
| } |
| |
| #define READ_ONE() \ |
| { \ |
| if (!max_interval-- || url_feof(pb)) \ |
| goto out; \ |
| tmp = tmp << 8 | get_byte(pb); \ |
| } |
| |
| /** |
| * \brief resync the stream on the next media packet with specified properties |
| * \param max_interval how many bytes to search for matching packet at most |
| * \param track track id the media packet must belong to, -1 for any |
| * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any |
| * \return timestamp of packet found |
| */ |
| static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) { |
| uint32_t tmp; |
| uint64_t last_pos; |
| uint64_t last_found_pos = 0; |
| int cur_track; |
| int64_t cur_timestamp = AV_NOPTS_VALUE; |
| int len; |
| ByteIOContext *pb = s->pb; |
| GXFPktType type; |
| tmp = get_be32(pb); |
| start: |
| while (tmp) |
| READ_ONE(); |
| READ_ONE(); |
| if (tmp != 1) |
| goto start; |
| last_pos = url_ftell(pb); |
| url_fseek(pb, -5, SEEK_CUR); |
| if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) { |
| url_fseek(pb, last_pos, SEEK_SET); |
| goto start; |
| } |
| get_byte(pb); |
| cur_track = get_byte(pb); |
| cur_timestamp = get_be32(pb); |
| last_found_pos = url_ftell(pb) - 16 - 6; |
| if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) { |
| url_fseek(pb, last_pos, SEEK_SET); |
| goto start; |
| } |
| out: |
| if (last_found_pos) |
| url_fseek(pb, last_found_pos, SEEK_SET); |
| return cur_timestamp; |
| } |
| |
| static int gxf_packet(AVFormatContext *s, AVPacket *pkt) { |
| ByteIOContext *pb = s->pb; |
| GXFPktType pkt_type; |
| int pkt_len; |
| while (!url_feof(pb)) { |
| AVStream *st; |
| int track_type, track_id, ret; |
| int field_nr, field_info, skip = 0; |
| int stream_index; |
| if (!parse_packet_header(pb, &pkt_type, &pkt_len)) { |
| if (!url_feof(pb)) |
| av_log(s, AV_LOG_ERROR, "sync lost\n"); |
| return -1; |
| } |
| if (pkt_type == PKT_FLT) { |
| gxf_read_index(s, pkt_len); |
| continue; |
| } |
| if (pkt_type != PKT_MEDIA) { |
| url_fskip(pb, pkt_len); |
| continue; |
| } |
| if (pkt_len < 16) { |
| av_log(s, AV_LOG_ERROR, "invalid media packet length\n"); |
| continue; |
| } |
| pkt_len -= 16; |
| track_type = get_byte(pb); |
| track_id = get_byte(pb); |
| stream_index = get_sindex(s, track_id, track_type); |
| if (stream_index < 0) |
| return stream_index; |
| st = s->streams[stream_index]; |
| field_nr = get_be32(pb); |
| field_info = get_be32(pb); |
| get_be32(pb); // "timeline" field number |
| get_byte(pb); // flags |
| get_byte(pb); // reserved |
| if (st->codec->codec_id == CODEC_ID_PCM_S24LE || |
| st->codec->codec_id == CODEC_ID_PCM_S16LE) { |
| int first = field_info >> 16; |
| int last = field_info & 0xffff; // last is exclusive |
| int bps = av_get_bits_per_sample(st->codec->codec_id)>>3; |
| if (first <= last && last*bps <= pkt_len) { |
| url_fskip(pb, first*bps); |
| skip = pkt_len - last*bps; |
| pkt_len = (last-first)*bps; |
| } else |
| av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n"); |
| } |
| ret = av_get_packet(pb, pkt, pkt_len); |
| if (skip) |
| url_fskip(pb, skip); |
| pkt->stream_index = stream_index; |
| pkt->dts = field_nr; |
| return ret; |
| } |
| return AVERROR(EIO); |
| } |
| |
| static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { |
| uint64_t pos; |
| uint64_t maxlen = 100 * 1024 * 1024; |
| AVStream *st = s->streams[0]; |
| int64_t start_time = s->streams[stream_index]->start_time; |
| int64_t found; |
| int idx; |
| if (timestamp < start_time) timestamp = start_time; |
| idx = av_index_search_timestamp(st, timestamp - start_time, |
| AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD); |
| if (idx < 0) |
| return -1; |
| pos = st->index_entries[idx].pos; |
| if (idx < st->nb_index_entries - 2) |
| maxlen = st->index_entries[idx + 2].pos - pos; |
| maxlen = FFMAX(maxlen, 200 * 1024); |
| url_fseek(s->pb, pos, SEEK_SET); |
| found = gxf_resync_media(s, maxlen, -1, timestamp); |
| if (FFABS(found - timestamp) > 4) |
| return -1; |
| return 0; |
| } |
| |
| static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index, |
| int64_t *pos, int64_t pos_limit) { |
| ByteIOContext *pb = s->pb; |
| int64_t res; |
| url_fseek(pb, *pos, SEEK_SET); |
| res = gxf_resync_media(s, pos_limit - *pos, -1, -1); |
| *pos = url_ftell(pb); |
| return res; |
| } |
| |
| AVInputFormat gxf_demuxer = { |
| "gxf", |
| NULL_IF_CONFIG_SMALL("GXF format"), |
| 0, |
| gxf_probe, |
| gxf_header, |
| gxf_packet, |
| NULL, |
| gxf_seek, |
| gxf_read_timestamp, |
| }; |
