[FFmpeg-cvslog] avformat/dhav: improve A/V sync
Paul B Mahol
git at videolan.org
Sat Nov 24 23:27:34 EET 2018
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sat Nov 24 21:40:52 2018 +0100| [24386b1707538621093460ea653e1c97876c5d5b] | committer: Paul B Mahol
avformat/dhav: improve A/V sync
Actual stored timestamps take only 16bits.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=24386b1707538621093460ea653e1c97876c5d5b
---
libavformat/dhav.c | 128 ++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 107 insertions(+), 21 deletions(-)
diff --git a/libavformat/dhav.c b/libavformat/dhav.c
index 467befad3c..b069afc713 100644
--- a/libavformat/dhav.c
+++ b/libavformat/dhav.c
@@ -20,25 +20,35 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include "libavutil/avassert.h"
+#include "libavutil/parseutils.h"
#include "avio_internal.h"
#include "avformat.h"
#include "internal.h"
typedef struct DHAVContext {
unsigned type;
+ unsigned subtype;
+ unsigned channel;
+ unsigned frame_subnumber;
+ unsigned frame_number;
+ unsigned date;
+ unsigned timestamp;
int width, height;
int video_codec;
int frame_rate;
- int channels;
+ int audio_channels;
int audio_codec;
int sample_rate;
- int64_t pts;
int video_stream_index;
int audio_stream_index;
} DHAVContext;
+typedef struct DHAVStream {
+ int64_t last_timestamp;
+ int64_t pts;
+} DHAVStream;
+
static int dhav_probe(AVProbeData *p)
{
if (!memcmp(p->buf, "DAHUA", 5))
@@ -74,6 +84,42 @@ static int dhav_read_header(AVFormatContext *s)
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,
@@ -108,7 +154,7 @@ static int parse_ext(AVFormatContext *s, int length)
length -= 8;
break;
case 0x83:
- dhav->channels = avio_r8(s->pb);
+ dhav->audio_channels = avio_r8(s->pb);
dhav->audio_codec = avio_r8(s->pb);
index = avio_r8(s->pb);
if (index < FF_ARRAY_ELEMS(sample_rates)) {
@@ -124,7 +170,7 @@ static int parse_ext(AVFormatContext *s, int length)
break;
case 0x8c:
avio_skip(s->pb, 1);
- dhav->channels = avio_r8(s->pb);
+ dhav->audio_channels = avio_r8(s->pb);
dhav->audio_codec = avio_r8(s->pb);
index = avio_r8(s->pb);
if (index < FF_ARRAY_ELEMS(sample_rates)) {
@@ -169,7 +215,7 @@ static int parse_ext(AVFormatContext *s, int length)
static int read_chunk(AVFormatContext *s)
{
DHAVContext *dhav = s->priv_data;
- unsigned size, skip;
+ unsigned frame_length, ext_length;
int64_t start, end;
int ret;
@@ -182,28 +228,31 @@ static int read_chunk(AVFormatContext *s)
return AVERROR_INVALIDDATA;
dhav->type = avio_r8(s->pb);
- avio_skip(s->pb, 3);
- dhav->pts = avio_rl32(s->pb);
- size = avio_rl32(s->pb);
- if (size < 24)
+ dhav->subtype = avio_r8(s->pb);
+ dhav->channel = avio_r8(s->pb);
+ dhav->frame_subnumber = avio_r8(s->pb);
+ dhav->frame_number = avio_rl32(s->pb);
+ frame_length = avio_rl32(s->pb);
+
+ if (frame_length < 24)
return AVERROR_INVALIDDATA;
if (dhav->type == 0xf1) {
- avio_skip(s->pb, size - 16);
+ avio_skip(s->pb, frame_length - 16);
return 0;
}
- avio_rl32(s->pb);
- avio_skip(s->pb, 2);
- skip = avio_r8(s->pb);
- avio_skip(s->pb, 1);
+ dhav->date = avio_rl32(s->pb);
+ dhav->timestamp = avio_rl16(s->pb);
+ ext_length = avio_r8(s->pb);
+ avio_skip(s->pb, 1); // checksum
- ret = parse_ext(s, skip);
+ ret = parse_ext(s, ext_length);
if (ret < 0)
return ret;
end = avio_tell(s->pb);
- return size - 8 - (end - start);
+ return frame_length - 8 - (end - start);
}
static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
@@ -222,6 +271,7 @@ static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
if (dhav->type == 0xfd && dhav->video_stream_index == -1) {
AVStream *st = avformat_new_stream(s, NULL);
+ DHAVStream *dst;
if (!st)
return AVERROR(ENOMEM);
@@ -238,11 +288,16 @@ static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
}
st->codecpar->width = dhav->width;
st->codecpar->height = dhav->height;
+ st->priv_data = dst = av_mallocz(sizeof(DHAVStream));
+ if (!st->priv_data)
+ return AVERROR(ENOMEM);
+ dst->last_timestamp = AV_NOPTS_VALUE;
dhav->video_stream_index = st->index;
- avpriv_set_pts_info(st, 64, 1, dhav->frame_rate);
+ avpriv_set_pts_info(st, 64, 1, 1000);
} else if (dhav->type == 0xf0 && dhav->audio_stream_index == -1) {
AVStream *st = avformat_new_stream(s, NULL);
+ DHAVStream *dst;
if (!st)
return AVERROR(ENOMEM);
@@ -261,11 +316,15 @@ static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
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->codecpar->channels = dhav->channels;
+ 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;
dhav->audio_stream_index = st->index;
- avpriv_set_pts_info(st, 64, ret, dhav->sample_rate);
+ avpriv_set_pts_info(st, 64, 1, 1000);
}
ret = av_get_packet(s->pb, pkt, ret);
@@ -274,7 +333,8 @@ static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
pkt->stream_index = dhav->type == 0xf0 ? dhav->audio_stream_index : dhav->video_stream_index;
if (dhav->type != 0xfc)
pkt->flags |= AV_PKT_FLAG_KEY;
- pkt->pts = dhav->pts;
+ if (pkt->stream_index >= 0)
+ pkt->pts = get_pts(s, s->streams[pkt->stream_index]->priv_data);
pkt->duration = 1;
pkt->pos = start;
if (avio_rl32(s->pb) != MKTAG('d','h','a','v'))
@@ -284,6 +344,31 @@ static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
return ret;
}
+static int dhav_read_seek(AVFormatContext *s, int stream_index,
+ int64_t timestamp, int flags)
+{
+ AVStream *st = s->streams[stream_index];
+ int index = av_index_search_timestamp(st, timestamp, flags);
+ int64_t pts;
+
+ if (index < 0)
+ return -1;
+ if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
+ return -1;
+
+ pts = st->index_entries[index].timestamp;
+
+ for (int n = 0; n < s->nb_streams; n++) {
+ AVStream *st = s->streams[n];
+ DHAVStream *dst = st->priv_data;
+
+ dst->pts = pts;
+ dst->last_timestamp = AV_NOPTS_VALUE;
+ }
+
+ return 0;
+}
+
AVInputFormat ff_dhav_demuxer = {
.name = "dhav",
.long_name = NULL_IF_CONFIG_SMALL("Video DAV"),
@@ -291,6 +376,7 @@ AVInputFormat ff_dhav_demuxer = {
.read_probe = dhav_probe,
.read_header = dhav_read_header,
.read_packet = dhav_read_packet,
+ .read_seek = dhav_read_seek,
.extensions = "dav",
.flags = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK,
};
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