From 907a051009d02b6b219558f9802d8b6cbf00f24a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Reimar=20D=C3=B6ffinger?= Date: Tue, 1 Aug 2006 10:19:25 +0000 Subject: [PATCH] Support for seeking, both with and without index and correct timestamps Originally committed as revision 5880 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavformat/gxf.c | 276 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 273 insertions(+), 3 deletions(-) diff --git a/libavformat/gxf.c b/libavformat/gxf.c index 09a60dbc0c..dccfdd7474 100644 --- a/libavformat/gxf.c +++ b/libavformat/gxf.c @@ -17,6 +17,7 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "avformat.h" +#include "common.h" typedef enum { PKT_MAP = 0xbc, @@ -26,6 +27,32 @@ typedef enum { PKT_UMF = 0xfd } pkt_type_t; +typedef enum { + MAT_NAME = 0x40, + MAT_FIRST_FIELD = 0x41, + MAT_LAST_FIELD = 0x42, + MAT_MARK_IN = 0x43, + MAT_MARK_OUT = 0x44, + MAT_SIZE = 0x45 +} mat_tag_t; + +typedef enum { + TRACK_NAME = 0x4c, + TRACK_AUX = 0x4d, + TRACK_VER = 0x4e, + TRACK_MPG_AUX = 0x4f, + TRACK_FPS = 0x50, + TRACK_LINES = 0x51, + TRACK_FPF = 0x52 +} track_tag_t; + +typedef struct { + int64_t first_field; + int64_t last_field; + AVRational frames_per_second; + int32_t fields_per_frame; +} st_info_t; + /** * \brief parses a packet header, extracting type and length * \param pb ByteIOContext to read header from @@ -147,11 +174,116 @@ static int get_sindex(AVFormatContext *s, int id, int format) { return s->nb_streams - 1; } +/** + * \brief filters out interesting tags from material information. + * \param len lenght 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, st_info_t *si) { + si->first_field = AV_NOPTS_VALUE; + si->last_field = AV_NOPTS_VALUE; + while (*len >= 2) { + mat_tag_t 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, st_info_t *si) { + si->frames_per_second = (AVRational){0, 0}; + si->fields_per_frame = 0; + while (*len >= 2) { + track_tag_t 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, "GXF: 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, "GXF: 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; pkt_type_t pkt_type; int map_len; int len; + AVRational main_timebase = {0, 0}; + st_info_t si; + int i; if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) { av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n"); return 0; @@ -168,6 +300,7 @@ static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) { 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 @@ -178,11 +311,14 @@ static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) { 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, "GXF: invalid track type %x\n", track_type); @@ -194,26 +330,125 @@ static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) { continue; } track_id &= 0x3f; - get_sindex(s, track_id, track_type); + 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, "GXF: 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, "GXF: 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, "GXF: sync lost in header\n"); + return -1; + } + } + if (pkt_type == PKT_UMF) { + if (len >= 9) { + AVRational fps; + len -= 9; + url_fskip(pb, 5); + 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, "GXF: UMF packet too short\n"); + } else + av_log(s, AV_LOG_INFO, "GXF: UMF packet missing\n"); + url_fskip(pb, len); + for (i = 0; i < s->nb_streams; i++) { + AVStream *st = s->streams[i]; + if (main_timebase.num && main_timebase.den) + st->time_base = main_timebase; + else { + st->start_time = st->duration = AV_NOPTS_VALUE; + } + } 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; + pkt_type_t type; + tmp = 0xff; +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; pkt_type_t pkt_type; int pkt_len; while (!url_feof(pb)) { int track_type, track_id, ret; + int field_nr; if (!parse_packet_header(pb, &pkt_type, &pkt_len)) { if (!url_feof(pb)) av_log(s, AV_LOG_ERROR, "GXF: 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; @@ -225,7 +460,7 @@ static int gxf_packet(AVFormatContext *s, AVPacket *pkt) { pkt_len -= 16; track_type = get_byte(pb); track_id = get_byte(pb); - get_be32(pb); // field number + field_nr = get_be32(pb); get_be32(pb); // field information get_be32(pb); // "timeline" field number get_byte(pb); // flags @@ -235,11 +470,45 @@ static int gxf_packet(AVFormatContext *s, AVPacket *pkt) { // as well. ret = av_get_packet(pb, pkt, pkt_len); pkt->stream_index = get_sindex(s, track_id, track_type); + pkt->pts = field_nr; return ret; } return AVERROR_IO; } +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 (ABS(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", "GXF format", @@ -248,5 +517,6 @@ AVInputFormat gxf_demuxer = { gxf_header, gxf_packet, NULL, - NULL, + gxf_seek, + gxf_read_timestamp, };