[SCM] libav/experimental: caching of timestamps for mpeg-ps so seeking is faster move (av_)find_stream_index() to utils.c as its usefull outside mpeg.c assert checking enabled, to find bugs quicker, should obviously be disabled later (av_)add_index_entry() inserts new entries so that the list stays ordered and updates entries if already in it (av_)index_search_timestamp() cleanup (kill ugly goto) and shorter
siretart at users.alioth.debian.org
siretart at users.alioth.debian.org
Sun Jun 30 15:38:57 UTC 2013
The following commit has been merged in the experimental branch:
commit b754978a3b0aa17e7794f64c69bf4491762797fd
Author: Michael Niedermayer <michaelni at gmx.at>
Date: Tue Jan 13 22:02:49 2004 +0000
caching of timestamps for mpeg-ps so seeking is faster
move (av_)find_stream_index() to utils.c as its usefull outside mpeg.c
assert checking enabled, to find bugs quicker, should obviously be disabled later
(av_)add_index_entry() inserts new entries so that the list stays ordered and updates entries if already in it
(av_)index_search_timestamp() cleanup (kill ugly goto) and shorter
Originally committed as revision 2697 to svn://svn.ffmpeg.org/ffmpeg/trunk
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 64bea9c..b098247 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -195,6 +195,9 @@ typedef struct AVIndexEntry {
int64_t pos;
int64_t timestamp;
#define AVINDEX_KEYFRAME 0x0001
+/* the following 2 flags indicate that the next/prev keyframe is known, and scaning for it isnt needed */
+#define AVINDEX_NEXT_KNOWN 0x0002
+#define AVINDEX_PREV_KNOWN 0x0004
int flags;
} AVIndexEntry;
@@ -544,6 +547,11 @@ AVStream *av_new_stream(AVFormatContext *s, int id);
void av_set_pts_info(AVFormatContext *s, int pts_wrap_bits,
int pts_num, int pts_den);
+int av_find_default_stream_index(AVFormatContext *s);
+int av_index_search_timestamp(AVStream *st, int timestamp);
+void av_add_index_entry(AVStream *st,
+ int64_t pos, int64_t timestamp, int flags);
+
/* media file output */
int av_set_parameters(AVFormatContext *s, AVFormatParameters *ap);
int av_write_header(AVFormatContext *s);
diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c
index 5fcc7f6..5bd7215 100644
--- a/libavformat/mpeg.c
+++ b/libavformat/mpeg.c
@@ -21,6 +21,9 @@
#define MAX_PAYLOAD_SIZE 4096
//#define DEBUG_SEEK
+#undef NDEBUG
+#include <assert.h>
+
typedef struct {
uint8_t buffer[MAX_PAYLOAD_SIZE];
int buffer_ptr;
@@ -902,6 +905,15 @@ static int mpegps_read_pes_header(AVFormatContext *s,
len -= 3;
}
}
+ if(dts != AV_NOPTS_VALUE && ppos){
+ int i;
+ for(i=0; i<s->nb_streams; i++){
+ if(startcode == s->streams[i]->id) {
+ av_add_index_entry(s->streams[i], *ppos, dts, 0 /* FIXME keyframe? */);
+ }
+ }
+ }
+
*pstart_code = startcode;
*ppts = pts;
*pdts = dts;
@@ -913,10 +925,10 @@ static int mpegps_read_packet(AVFormatContext *s,
{
AVStream *st;
int len, startcode, i, type, codec_id;
- int64_t pts, dts;
+ int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work
redo:
- len = mpegps_read_pes_header(s, NULL, &startcode, &pts, &dts, 1);
+ len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts, 1);
if (len < 0)
return len;
@@ -1022,27 +1034,13 @@ static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
return dts;
}
-static int find_stream_index(AVFormatContext *s)
-{
- int i;
- AVStream *st;
-
- if (s->nb_streams <= 0)
- return -1;
- for(i = 0; i < s->nb_streams; i++) {
- st = s->streams[i];
- if (st->codec.codec_type == CODEC_TYPE_VIDEO) {
- return i;
- }
- }
- return 0;
-}
-
static int mpegps_read_seek(AVFormatContext *s,
int stream_index, int64_t timestamp)
{
int64_t pos_min, pos_max, pos;
int64_t dts_min, dts_max, dts;
+ int index;
+ AVStream *st;
timestamp = (timestamp * 90000) / AV_TIME_BASE;
@@ -1052,19 +1050,56 @@ static int mpegps_read_seek(AVFormatContext *s,
/* XXX: find stream_index by looking at the first PES packet found */
if (stream_index < 0) {
- stream_index = find_stream_index(s);
+ stream_index = av_find_default_stream_index(s);
if (stream_index < 0)
return -1;
}
- pos_min = 0;
- dts_min = mpegps_read_dts(s, stream_index, &pos_min, 1);
- if (dts_min == AV_NOPTS_VALUE) {
- /* we can reach this case only if no PTS are present in
- the whole stream */
- return -1;
+
+ dts_max=
+ dts_min= AV_NOPTS_VALUE;
+
+ st= s->streams[stream_index];
+ if(st->index_entries){
+ AVIndexEntry *e;
+
+ index= av_index_search_timestamp(st, timestamp);
+ e= &st->index_entries[index];
+ if(e->timestamp <= timestamp){
+ pos_min= e->pos;
+ dts_min= e->timestamp;
+#ifdef DEBUG_SEEK
+ printf("unsing cached pos_min=0x%llx dts_min=%0.3f\n",
+ pos_min,dts_min / 90000.0);
+#endif
+ }else{
+ assert(index==0);
+ }
+ index++;
+ if(index < st->nb_index_entries){
+ e= &st->index_entries[index];
+ assert(e->timestamp >= timestamp);
+ pos_max= e->pos;
+ dts_max= e->timestamp;
+#ifdef DEBUG_SEEK
+ printf("unsing cached pos_max=0x%llx dts_max=%0.3f\n",
+ pos_max,dts_max / 90000.0);
+#endif
+ }
+ }
+
+ if(dts_min == AV_NOPTS_VALUE){
+ pos_min = 0;
+ dts_min = mpegps_read_dts(s, stream_index, &pos_min, 1);
+ if (dts_min == AV_NOPTS_VALUE) {
+ /* we can reach this case only if no PTS are present in
+ the whole stream */
+ return -1;
+ }
+ }
+ if(dts_max == AV_NOPTS_VALUE){
+ pos_max = url_filesize(url_fileno(&s->pb)) - 1;
+ dts_max = mpegps_read_dts(s, stream_index, &pos_max, 0);
}
- pos_max = url_filesize(url_fileno(&s->pb)) - 1;
- dts_max = mpegps_read_dts(s, stream_index, &pos_max, 0);
while (pos_min <= pos_max) {
#ifdef DEBUG_SEEK
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 81f8330..18f031d 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -18,6 +18,9 @@
*/
#include "avformat.h"
+#undef NDEBUG
+#include <assert.h>
+
AVInputFormat *first_iformat;
AVOutputFormat *first_oformat;
AVImageFormat *first_image_format;
@@ -811,6 +814,22 @@ static void flush_packet_queue(AVFormatContext *s)
/*******************************************************/
/* seek support */
+int av_find_default_stream_index(AVFormatContext *s)
+{
+ int i;
+ AVStream *st;
+
+ if (s->nb_streams <= 0)
+ return -1;
+ for(i = 0; i < s->nb_streams; i++) {
+ st = s->streams[i];
+ if (st->codec.codec_type == CODEC_TYPE_VIDEO) {
+ return i;
+ }
+ }
+ return 0;
+}
+
/* flush the frame reader */
static void av_read_frame_flush(AVFormatContext *s)
{
@@ -841,22 +860,42 @@ static void av_read_frame_flush(AVFormatContext *s)
}
}
-static void add_index_entry(AVStream *st,
+/* add a index entry into a sorted list updateing if it is already there */
+void av_add_index_entry(AVStream *st,
int64_t pos, int64_t timestamp, int flags)
{
AVIndexEntry *entries, *ie;
+ int index;
entries = av_fast_realloc(st->index_entries,
&st->index_entries_allocated_size,
(st->nb_index_entries + 1) *
sizeof(AVIndexEntry));
- if (entries) {
- st->index_entries = entries;
- ie = &entries[st->nb_index_entries++];
- ie->pos = pos;
- ie->timestamp = timestamp;
- ie->flags = flags;
- }
+ st->index_entries= entries;
+
+ if(st->nb_index_entries){
+ index= av_index_search_timestamp(st, timestamp);
+ ie= &entries[index];
+
+ if(ie->timestamp != timestamp){
+ if(ie->timestamp < timestamp){
+ index++; //index points to next instead of previous entry, maybe nonexistant
+ ie= &st->index_entries[index];
+ }else
+ assert(index==0);
+
+ if(index != st->nb_index_entries){
+ assert(index < st->nb_index_entries);
+ memmove(entries + index + 1, entries + index, sizeof(AVIndexEntry)*(st->nb_index_entries - index));
+ }
+ st->nb_index_entries++;
+ }
+ }else
+ ie= &entries[st->nb_index_entries++];
+
+ ie->pos = pos;
+ ie->timestamp = timestamp;
+ ie->flags = flags;
}
/* build an index for raw streams using a parser */
@@ -876,7 +915,7 @@ static void av_build_index_raw(AVFormatContext *s)
break;
if (pkt->stream_index == 0 && st->parser &&
(pkt->flags & PKT_FLAG_KEY)) {
- add_index_entry(st, st->parser->frame_offset, pkt->dts,
+ av_add_index_entry(st, st->parser->frame_offset, pkt->dts,
AVINDEX_KEYFRAME);
}
av_free_packet(pkt);
@@ -899,9 +938,10 @@ static int is_raw_stream(AVFormatContext *s)
/* return the largest index entry whose timestamp is <=
wanted_timestamp */
-static int index_search_timestamp(AVIndexEntry *entries,
- int nb_entries, int wanted_timestamp)
+int av_index_search_timestamp(AVStream *st, int wanted_timestamp)
{
+ AVIndexEntry *entries= st->index_entries;
+ int nb_entries= st->nb_index_entries;
int a, b, m;
int64_t timestamp;
@@ -910,22 +950,17 @@ static int index_search_timestamp(AVIndexEntry *entries,
a = 0;
b = nb_entries - 1;
- while (a <= b) {
- m = (a + b) >> 1;
+
+ while (a < b) {
+ m = (a + b + 1) >> 1;
timestamp = entries[m].timestamp;
- if (timestamp == wanted_timestamp)
- goto found;
- else if (timestamp > wanted_timestamp) {
+ if (timestamp > wanted_timestamp) {
b = m - 1;
} else {
- a = m + 1;
+ a = m;
}
}
- m = a;
- if (m > 0)
- m--;
- found:
- return m;
+ return a;
}
static int av_seek_frame_generic(AVFormatContext *s,
@@ -947,8 +982,7 @@ static int av_seek_frame_generic(AVFormatContext *s,
if (stream_index < 0)
stream_index = 0;
st = s->streams[stream_index];
- index = index_search_timestamp(st->index_entries, st->nb_index_entries,
- timestamp);
+ index = av_index_search_timestamp(st, timestamp);
if (index < 0)
return -1;
--
Libav/FFmpeg packaging
More information about the pkg-multimedia-commits
mailing list