forked from KolibriOS/kolibrios
605 lines
20 KiB
C
605 lines
20 KiB
C
/*
|
|
* 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/channel_layout.h"
|
|
#include "libavutil/common.h"
|
|
#include "avformat.h"
|
|
#include "internal.h"
|
|
#include "gxf.h"
|
|
#include "libavcodec/mpeg12data.h"
|
|
|
|
struct gxf_stream_info {
|
|
int64_t first_field;
|
|
int64_t last_field;
|
|
AVRational frames_per_second;
|
|
int32_t fields_per_frame;
|
|
int64_t track_aux_data;
|
|
};
|
|
|
|
/**
|
|
* @brief parse gxf timecode and add it to metadata
|
|
*/
|
|
static int add_timecode_metadata(AVDictionary **pm, const char *key, uint32_t timecode, int fields_per_frame)
|
|
{
|
|
char tmp[128];
|
|
int field = timecode & 0xff;
|
|
int frame = fields_per_frame ? field / fields_per_frame : field;
|
|
int second = (timecode >> 8) & 0xff;
|
|
int minute = (timecode >> 16) & 0xff;
|
|
int hour = (timecode >> 24) & 0x1f;
|
|
int drop = (timecode >> 29) & 1;
|
|
// bit 30: color_frame, unused
|
|
// ignore invalid time code
|
|
if (timecode >> 31)
|
|
return 0;
|
|
snprintf(tmp, sizeof(tmp), "%02d:%02d:%02d%c%02d",
|
|
hour, minute, second, drop ? ';' : ':', frame);
|
|
return av_dict_set(pm, key, tmp, 0);
|
|
}
|
|
|
|
/**
|
|
* @brief parses a packet header, extracting type and length
|
|
* @param pb AVIOContext 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(AVIOContext *pb, GXFPktType *type, int *length) {
|
|
if (avio_rb32(pb))
|
|
return 0;
|
|
if (avio_r8(pb) != 1)
|
|
return 0;
|
|
*type = avio_r8(pb);
|
|
*length = avio_rb32(pb);
|
|
if ((*length >> 24) || *length < 16)
|
|
return 0;
|
|
*length -= 16;
|
|
if (avio_rb32(pb))
|
|
return 0;
|
|
if (avio_r8(pb) != 0xe1)
|
|
return 0;
|
|
if (avio_r8(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 id 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;
|
|
i = ff_find_stream_index(s, id);
|
|
if (i >= 0)
|
|
return i;
|
|
st = avformat_new_stream(s, NULL);
|
|
if (!st)
|
|
return AVERROR(ENOMEM);
|
|
st->id = id;
|
|
switch (format) {
|
|
case 3:
|
|
case 4:
|
|
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
|
|
st->codec->codec_id = AV_CODEC_ID_MJPEG;
|
|
break;
|
|
case 13:
|
|
case 14:
|
|
case 15:
|
|
case 16:
|
|
case 25:
|
|
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
|
|
st->codec->codec_id = AV_CODEC_ID_DVVIDEO;
|
|
break;
|
|
case 11:
|
|
case 12:
|
|
case 20:
|
|
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
|
|
st->codec->codec_id = AV_CODEC_ID_MPEG2VIDEO;
|
|
st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
|
|
break;
|
|
case 22:
|
|
case 23:
|
|
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
|
|
st->codec->codec_id = AV_CODEC_ID_MPEG1VIDEO;
|
|
st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
|
|
break;
|
|
case 9:
|
|
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
|
|
st->codec->codec_id = AV_CODEC_ID_PCM_S24LE;
|
|
st->codec->channels = 1;
|
|
st->codec->channel_layout = AV_CH_LAYOUT_MONO;
|
|
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 = AVMEDIA_TYPE_AUDIO;
|
|
st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
|
|
st->codec->channels = 1;
|
|
st->codec->channel_layout = AV_CH_LAYOUT_MONO;
|
|
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 = AVMEDIA_TYPE_AUDIO;
|
|
st->codec->codec_id = AV_CODEC_ID_AC3;
|
|
st->codec->channels = 2;
|
|
st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
|
|
st->codec->sample_rate = 48000;
|
|
break;
|
|
case 26: /* AVCi50 / AVCi100 (AVC Intra) */
|
|
case 29: /* AVCHD */
|
|
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
|
|
st->codec->codec_id = CODEC_ID_H264;
|
|
st->need_parsing = AVSTREAM_PARSE_HEADERS;
|
|
break;
|
|
// timecode tracks:
|
|
case 7:
|
|
case 8:
|
|
case 24:
|
|
st->codec->codec_type = AVMEDIA_TYPE_DATA;
|
|
st->codec->codec_id = AV_CODEC_ID_NONE;
|
|
break;
|
|
case 30:
|
|
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
|
|
st->codec->codec_id = AV_CODEC_ID_DNXHD;
|
|
break;
|
|
default:
|
|
st->codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
|
|
st->codec->codec_id = AV_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(AVIOContext *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 = avio_r8(pb);
|
|
int tlen = avio_r8(pb);
|
|
*len -= 2;
|
|
if (tlen > *len)
|
|
return;
|
|
*len -= tlen;
|
|
if (tlen == 4) {
|
|
uint32_t value = avio_rb32(pb);
|
|
if (tag == MAT_FIRST_FIELD)
|
|
si->first_field = value;
|
|
else if (tag == MAT_LAST_FIELD)
|
|
si->last_field = value;
|
|
} else
|
|
avio_skip(pb, tlen);
|
|
}
|
|
}
|
|
|
|
static const AVRational frame_rate_tab[] = {
|
|
{ 60, 1},
|
|
{60000, 1001},
|
|
{ 50, 1},
|
|
{ 30, 1},
|
|
{30000, 1001},
|
|
{ 25, 1},
|
|
{ 24, 1},
|
|
{24000, 1001},
|
|
{ 0, 0},
|
|
};
|
|
|
|
/**
|
|
* @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) {
|
|
if (fps < 1 || fps > 9) fps = 9;
|
|
return frame_rate_tab[fps - 1];
|
|
}
|
|
|
|
/**
|
|
* @brief convert UMF attributes flags to AVRational fps
|
|
* @param flags UMF flags to convert
|
|
* @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(AVIOContext *pb, int *len, struct gxf_stream_info *si) {
|
|
si->frames_per_second = (AVRational){0, 0};
|
|
si->fields_per_frame = 0;
|
|
si->track_aux_data = 0x80000000;
|
|
while (*len >= 2) {
|
|
GXFTrackTag tag = avio_r8(pb);
|
|
int tlen = avio_r8(pb);
|
|
*len -= 2;
|
|
if (tlen > *len)
|
|
return;
|
|
*len -= tlen;
|
|
if (tlen == 4) {
|
|
uint32_t value = avio_rb32(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 if (tlen == 8 && tag == TRACK_AUX)
|
|
si->track_aux_data = avio_rl64(pb);
|
|
else
|
|
avio_skip(pb, tlen);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @brief read index from FLT packet into stream 0 av_index
|
|
*/
|
|
static void gxf_read_index(AVFormatContext *s, int pkt_len) {
|
|
AVIOContext *pb = s->pb;
|
|
AVStream *st;
|
|
uint32_t fields_per_map = avio_rl32(pb);
|
|
uint32_t map_cnt = avio_rl32(pb);
|
|
int i;
|
|
pkt_len -= 8;
|
|
if ((s->flags & AVFMT_FLAG_IGNIDX) || !s->streams) {
|
|
avio_skip(pb, pkt_len);
|
|
return;
|
|
}
|
|
st = s->streams[0];
|
|
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");
|
|
avio_skip(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)avio_rl32(pb) * 1024,
|
|
i * (uint64_t)fields_per_map + 1, 0, 0, 0);
|
|
avio_skip(pb, pkt_len);
|
|
}
|
|
|
|
static int gxf_header(AVFormatContext *s) {
|
|
AVIOContext *pb = s->pb;
|
|
GXFPktType pkt_type;
|
|
int map_len;
|
|
int len;
|
|
AVRational main_timebase = {0, 0};
|
|
struct gxf_stream_info *si = s->priv_data;
|
|
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 (avio_r8(pb) != 0x0e0 || avio_r8(pb) != 0xff) {
|
|
av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
|
|
return 0;
|
|
}
|
|
map_len -= 2;
|
|
len = avio_rb16(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);
|
|
avio_skip(pb, len);
|
|
map_len -= 2;
|
|
len = avio_rb16(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 = avio_r8(pb);
|
|
track_id = avio_r8(pb);
|
|
track_len = avio_rb16(pb);
|
|
len -= 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;
|
|
gxf_track_tags(pb, &track_len, si);
|
|
// check for timecode tracks
|
|
if (track_type == 7 || track_type == 8 || track_type == 24) {
|
|
add_timecode_metadata(&s->metadata, "timecode",
|
|
si->track_aux_data & 0xffffffff,
|
|
si->fields_per_frame);
|
|
|
|
}
|
|
avio_skip(pb, track_len);
|
|
|
|
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 * 2;
|
|
}
|
|
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)
|
|
avio_skip(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;
|
|
avio_skip(pb, 5); // preamble
|
|
avio_skip(pb, 0x30); // payload description
|
|
fps = fps_umf2avr(avio_rl32(pb));
|
|
if (!main_timebase.num || !main_timebase.den) {
|
|
av_log(s, AV_LOG_WARNING, "No FPS track tag, using UMF fps tag."
|
|
" This might give wrong results.\n");
|
|
// this may not always be correct, but simply the best we can get
|
|
main_timebase.num = fps.den;
|
|
main_timebase.den = fps.num * 2;
|
|
}
|
|
|
|
if (len >= 0x18) {
|
|
len -= 0x18;
|
|
avio_skip(pb, 0x10);
|
|
add_timecode_metadata(&s->metadata, "timecode_at_mark_in",
|
|
avio_rl32(pb), si->fields_per_frame);
|
|
add_timecode_metadata(&s->metadata, "timecode_at_mark_out",
|
|
avio_rl32(pb), si->fields_per_frame);
|
|
}
|
|
} else
|
|
av_log(s, AV_LOG_INFO, "UMF packet too short\n");
|
|
} else
|
|
av_log(s, AV_LOG_INFO, "UMF packet missing\n");
|
|
avio_skip(pb, len);
|
|
// set a fallback value, 60000/1001 is specified for audio-only files
|
|
// so use that regardless of why we do not know the video frame rate.
|
|
if (!main_timebase.num || !main_timebase.den)
|
|
main_timebase = (AVRational){1001, 60000};
|
|
for (i = 0; i < s->nb_streams; i++) {
|
|
AVStream *st = s->streams[i];
|
|
avpriv_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 | avio_r8(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;
|
|
AVIOContext *pb = s->pb;
|
|
GXFPktType type;
|
|
tmp = avio_rb32(pb);
|
|
start:
|
|
while (tmp)
|
|
READ_ONE();
|
|
READ_ONE();
|
|
if (tmp != 1)
|
|
goto start;
|
|
last_pos = avio_tell(pb);
|
|
if (avio_seek(pb, -5, SEEK_CUR) < 0)
|
|
goto out;
|
|
if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
|
|
if (avio_seek(pb, last_pos, SEEK_SET) < 0)
|
|
goto out;
|
|
goto start;
|
|
}
|
|
avio_r8(pb);
|
|
cur_track = avio_r8(pb);
|
|
cur_timestamp = avio_rb32(pb);
|
|
last_found_pos = avio_tell(pb) - 16 - 6;
|
|
if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
|
|
if (avio_seek(pb, last_pos, SEEK_SET) >= 0)
|
|
goto start;
|
|
}
|
|
out:
|
|
if (last_found_pos)
|
|
avio_seek(pb, last_found_pos, SEEK_SET);
|
|
return cur_timestamp;
|
|
}
|
|
|
|
static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
|
|
AVIOContext *pb = s->pb;
|
|
GXFPktType pkt_type;
|
|
int pkt_len;
|
|
struct gxf_stream_info *si = s->priv_data;
|
|
|
|
while (!pb->eof_reached) {
|
|
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) {
|
|
avio_skip(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 = avio_r8(pb);
|
|
track_id = avio_r8(pb);
|
|
stream_index = get_sindex(s, track_id, track_type);
|
|
if (stream_index < 0)
|
|
return stream_index;
|
|
st = s->streams[stream_index];
|
|
field_nr = avio_rb32(pb);
|
|
field_info = avio_rb32(pb);
|
|
avio_rb32(pb); // "timeline" field number
|
|
avio_r8(pb); // flags
|
|
avio_r8(pb); // reserved
|
|
if (st->codec->codec_id == AV_CODEC_ID_PCM_S24LE ||
|
|
st->codec->codec_id == AV_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) {
|
|
avio_skip(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)
|
|
avio_skip(pb, skip);
|
|
pkt->stream_index = stream_index;
|
|
pkt->dts = field_nr;
|
|
|
|
//set duration manually for DV or else lavf misdetects the frame rate
|
|
if (st->codec->codec_id == AV_CODEC_ID_DVVIDEO)
|
|
pkt->duration = si->fields_per_frame;
|
|
|
|
return ret;
|
|
}
|
|
return AVERROR_EOF;
|
|
}
|
|
|
|
static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
|
|
int res = 0;
|
|
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);
|
|
res = avio_seek(s->pb, pos, SEEK_SET);
|
|
if (res < 0)
|
|
return res;
|
|
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) {
|
|
AVIOContext *pb = s->pb;
|
|
int64_t res;
|
|
if (avio_seek(pb, *pos, SEEK_SET) < 0)
|
|
return AV_NOPTS_VALUE;
|
|
res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
|
|
*pos = avio_tell(pb);
|
|
return res;
|
|
}
|
|
|
|
AVInputFormat ff_gxf_demuxer = {
|
|
.name = "gxf",
|
|
.long_name = NULL_IF_CONFIG_SMALL("GXF (General eXchange Format)"),
|
|
.priv_data_size = sizeof(struct gxf_stream_info),
|
|
.read_probe = gxf_probe,
|
|
.read_header = gxf_header,
|
|
.read_packet = gxf_packet,
|
|
.read_seek = gxf_seek,
|
|
.read_timestamp = gxf_read_timestamp,
|
|
};
|