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avformat/dhav: improve seeking

This commit is contained in:
Paul B Mahol 2019-12-25 19:35:27 +01:00
parent d6553e2e60
commit e3dca0744d
1 changed files with 130 additions and 81 deletions
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211
libavformat/dhav.c
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@ -40,6 +40,7 @@ typedef struct DHAVContext {
int audio_codec;
int sample_rate;
int64_t last_good_pos;
int64_t duration;
int video_stream_index;
int audio_stream_index;
@ -47,6 +48,7 @@ typedef struct DHAVContext {
typedef struct DHAVStream {
int64_t last_timestamp;
int64_t last_time;
int64_t pts;
} DHAVStream;
@ -66,77 +68,6 @@ static int dhav_probe(const AVProbeData *p)
return 0;
}
static int dhav_read_header(AVFormatContext *s)
{
DHAVContext *dhav = s->priv_data;
uint8_t signature[5];
ffio_ensure_seekback(s->pb, 5);
avio_read(s->pb, signature, sizeof(signature));
if (!memcmp(signature, "DAHUA", 5)) {
avio_skip(s->pb, 0x400 - 5);
dhav->last_good_pos = avio_tell(s->pb);
} else {
if (!memcmp(signature, "DHAV", 4)) {
avio_seek(s->pb, -5, SEEK_CUR);
dhav->last_good_pos = avio_tell(s->pb);
} else if (s->pb->seekable) {
avio_seek(s->pb, avio_size(s->pb) - 8, SEEK_SET);
while (avio_rl32(s->pb) == MKTAG('d','h','a','v')) {
int seek_back;
seek_back = avio_rl32(s->pb) + 8;
dhav->last_good_pos = avio_tell(s->pb);
if (dhav->last_good_pos < seek_back)
break;
avio_seek(s->pb, -seek_back, SEEK_CUR);
}
}
}
s->ctx_flags |= AVFMTCTX_NOHEADER;
dhav->video_stream_index = -1;
dhav->audio_stream_index = -1;
return 0;
}
static int64_t get_pts(AVFormatContext *s, DHAVStream *st)
{
DHAVContext *dhav = s->priv_data;
/*
int year, month, day, hour, min, sec;
struct tm timeinfo;
sec = dhav->date & 0x3F;
min = (dhav->date >> 6) & 0x3F;
hour = (dhav->date >> 12) & 0x1F;
day = (dhav->date >> 17) & 0x1F;
month = (dhav->date >> 22) & 0x0F;
year = ((dhav->date >> 26) & 0x3F) + 2000;
timeinfo.tm_year = year - 1900;
timeinfo.tm_mon = month - 1;
timeinfo.tm_mday = day;
timeinfo.tm_hour = hour;
timeinfo.tm_min = min;
timeinfo.tm_sec = sec;*/
if (st->last_timestamp == AV_NOPTS_VALUE) {
st->last_timestamp = dhav->timestamp;
}
if (st->last_timestamp <= dhav->timestamp) {
st->pts += dhav->timestamp - st->last_timestamp;
} else {
st->pts += 65535 + dhav->timestamp - st->last_timestamp;
}
st->last_timestamp = dhav->timestamp;
return st->pts;
}
static const uint32_t sample_rates[] = {
8000, 4000, 8000, 11025, 16000,
20000, 22050, 32000, 44100, 48000,
@ -264,15 +195,15 @@ static int read_chunk(AVFormatContext *s)
dhav->frame_subnumber = avio_r8(s->pb);
dhav->frame_number = avio_rl32(s->pb);
frame_length = avio_rl32(s->pb);
dhav->date = avio_rl32(s->pb);
if (frame_length < 24)
return AVERROR_INVALIDDATA;
if (dhav->type == 0xf1) {
ret = avio_skip(s->pb, frame_length - 16);
ret = avio_skip(s->pb, frame_length - 20);
return ret < 0 ? ret : 0;
}
dhav->date = avio_rl32(s->pb);
dhav->timestamp = avio_rl16(s->pb);
ext_length = avio_r8(s->pb);
avio_skip(s->pb, 1); // checksum
@ -286,10 +217,125 @@ static int read_chunk(AVFormatContext *s)
return frame_length - 8 - (end - start);
}
static void get_timeinfo(unsigned date, struct tm *timeinfo)
{
int year, month, day, hour, min, sec;
sec = date & 0x3F;
min = (date >> 6) & 0x3F;
hour = (date >> 12) & 0x1F;
day = (date >> 17) & 0x1F;
month = (date >> 22) & 0x0F;
year = ((date >> 26) & 0x3F) + 2000;
timeinfo->tm_year = year - 1900;
timeinfo->tm_mon = month - 1;
timeinfo->tm_mday = day;
timeinfo->tm_hour = hour;
timeinfo->tm_min = min;
timeinfo->tm_sec = sec;
}
static int64_t get_duration(AVFormatContext *s)
{
DHAVContext *dhav = s->priv_data;
int64_t start_pos = avio_tell(s->pb);
int64_t start = 0, end = 0;
struct tm timeinfo;
if (!s->pb->seekable)
return 0;
avio_seek(s->pb, avio_size(s->pb) - 8, SEEK_SET);
if (avio_rl32(s->pb) == MKTAG('d','h','a','v')) {
int seek_back = avio_rl32(s->pb);
avio_seek(s->pb, -seek_back, SEEK_CUR);
read_chunk(s);
get_timeinfo(dhav->date, &timeinfo);
end = av_timegm(&timeinfo) * 1000LL;
} else {
avio_seek(s->pb, start_pos, SEEK_SET);
return 0;
}
avio_seek(s->pb, start_pos, SEEK_SET);
read_chunk(s);
get_timeinfo(dhav->date, &timeinfo);
start = av_timegm(&timeinfo) * 1000LL;
avio_seek(s->pb, start_pos, SEEK_SET);
return end - start;
}
static int dhav_read_header(AVFormatContext *s)
{
DHAVContext *dhav = s->priv_data;
uint8_t signature[5];
ffio_ensure_seekback(s->pb, 5);
avio_read(s->pb, signature, sizeof(signature));
if (!memcmp(signature, "DAHUA", 5)) {
avio_skip(s->pb, 0x400 - 5);
dhav->last_good_pos = avio_tell(s->pb);
} else {
if (!memcmp(signature, "DHAV", 4)) {
avio_seek(s->pb, -5, SEEK_CUR);
dhav->last_good_pos = avio_tell(s->pb);
} else if (s->pb->seekable) {
avio_seek(s->pb, avio_size(s->pb) - 8, SEEK_SET);
while (avio_rl32(s->pb) == MKTAG('d','h','a','v')) {
int seek_back;
seek_back = avio_rl32(s->pb) + 8;
dhav->last_good_pos = avio_tell(s->pb);
avio_seek(s->pb, -seek_back, SEEK_CUR);
}
avio_seek(s->pb, dhav->last_good_pos, SEEK_SET);
}
}
dhav->duration = get_duration(s);
dhav->last_good_pos = avio_tell(s->pb);
s->ctx_flags |= AVFMTCTX_NOHEADER;
dhav->video_stream_index = -1;
dhav->audio_stream_index = -1;
return 0;
}
static int64_t get_pts(AVFormatContext *s, int stream_index)
{
DHAVStream *dst = s->streams[stream_index]->priv_data;
DHAVContext *dhav = s->priv_data;
struct tm timeinfo;
time_t t;
get_timeinfo(dhav->date, &timeinfo);
t = av_timegm(&timeinfo);
if (dst->last_time == t) {
int64_t diff = dhav->timestamp - dst->last_timestamp;
if (diff < 0)
diff += 65535;
dst->pts += diff;
} else {
dst->pts = t * 1000LL;
}
dst->last_time = t;
dst->last_timestamp = dhav->timestamp;
return dst->pts;
}
static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
{
DHAVContext *dhav = s->priv_data;
int ret, stream_index;
int size, ret, stream_index;
retry:
while ((ret = read_chunk(s)) == 0)
@ -315,6 +361,7 @@ retry:
case 0xc: st->codecpar->codec_id = AV_CODEC_ID_HEVC; break;
default: avpriv_request_sample(s, "Unknown video codec %X\n", dhav->video_codec);
}
st->duration = dhav->duration;
st->codecpar->width = dhav->width;
st->codecpar->height = dhav->height;
st->avg_frame_rate.num = dhav->frame_rate;
@ -322,7 +369,7 @@ retry:
st->priv_data = dst = av_mallocz(sizeof(DHAVStream));
if (!st->priv_data)
return AVERROR(ENOMEM);
dst->last_timestamp = AV_NOPTS_VALUE;
dst->last_time = AV_NOPTS_VALUE;
dhav->video_stream_index = st->index;
avpriv_set_pts_info(st, 64, 1, 1000);
@ -347,12 +394,13 @@ retry:
case 0x0d: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_MS; break;
default: avpriv_request_sample(s, "Unknown audio codec %X\n", dhav->audio_codec);
}
st->duration = dhav->duration;
st->codecpar->channels = dhav->audio_channels;
st->codecpar->sample_rate = dhav->sample_rate;
st->priv_data = dst = av_mallocz(sizeof(DHAVStream));
if (!st->priv_data)
return AVERROR(ENOMEM);
dst->last_timestamp = AV_NOPTS_VALUE;
dst->last_time = AV_NOPTS_VALUE;
dhav->audio_stream_index = st->index;
avpriv_set_pts_info(st, 64, 1, 1000);
@ -366,15 +414,16 @@ retry:
goto retry;
}
ret = av_get_packet(s->pb, pkt, ret);
size = ret;
ret = av_get_packet(s->pb, pkt, size);
if (ret < 0)
return ret;
pkt->stream_index = stream_index;
if (dhav->type != 0xfc)
pkt->flags |= AV_PKT_FLAG_KEY;
if (pkt->stream_index >= 0)
pkt->pts = get_pts(s, s->streams[pkt->stream_index]->priv_data);
pkt->duration = 1;
if (pkt->stream_index >= 0)
pkt->pts = get_pts(s, pkt->stream_index);
pkt->pos = dhav->last_good_pos;
if (avio_rl32(s->pb) == MKTAG('d','h','a','v'))
avio_skip(s->pb, 4);
@ -402,7 +451,7 @@ static int dhav_read_seek(AVFormatContext *s, int stream_index,
DHAVStream *dst = st->priv_data;
dst->pts = pts;
dst->last_timestamp = AV_NOPTS_VALUE;
dst->last_time = AV_NOPTS_VALUE;
}
dhav->last_good_pos = avio_tell(s->pb);
@ -418,5 +467,5 @@ AVInputFormat ff_dhav_demuxer = {
.read_packet = dhav_read_packet,
.read_seek = dhav_read_seek,
.extensions = "dav",
.flags = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK,
.flags = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK | AVFMT_TS_DISCONT | AVFMT_TS_NONSTRICT,
};