From a8dd8dc6e9a419758006dc212fb590991e927030 Mon Sep 17 00:00:00 2001
From: Ivan Schreter <schreter@gmx.net>
Date: Sat, 22 Aug 2009 16:07:50 +0000
Subject: [PATCH] Use generic multi-stream key frame finding routine to
 implement read_seek2 and map read_seek to read_seek2.

Originally committed as revision 19681 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavformat/mpegts.c      | 81 ++++++++++++++++++++++++++++++++-------
 tests/seek.regression.ref | 58 +++++++++++++---------------
 2 files changed, 94 insertions(+), 45 deletions(-)

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index 6c0c314f42..e3bdc6b658 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -28,6 +28,7 @@
 #include "avformat.h"
 #include "mpegts.h"
 #include "internal.h"
+#include "seek.h"
 
 /* 1.0 second at 24Mbit/s */
 #define MAX_SCAN_PACKETS 32000
@@ -1521,29 +1522,81 @@ static int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index,
     return timestamp;
 }
 
-static int read_seek(AVFormatContext *s, int stream_index, int64_t target_ts, int flags){
-    MpegTSContext *ts = s->priv_data;
-    uint8_t buf[TS_PACKET_SIZE];
+static int read_seek(AVFormatContext *s, int stream_index, int64_t target_ts, int flags);
+
+static int read_seek2(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t target_ts, int64_t max_ts, int flags)
+{
     int64_t pos;
 
-    if(av_seek_frame_binary(s, stream_index, target_ts, flags) < 0)
-        return -1;
+    int64_t ts_ret, ts_adj;
+    int stream_index_gen_search;
+    AVStream *st;
+    AVParserState *backup;
 
-    pos= url_ftell(s->pb);
+    backup = ff_store_parser_state(s);
 
-    for(;;) {
-        url_fseek(s->pb, pos, SEEK_SET);
-        if (get_buffer(s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)
+    // detect direction of seeking for search purposes
+    flags |= (target_ts - min_ts > (uint64_t)(max_ts - target_ts)) ? AVSEEK_FLAG_BACKWARD : 0;
+
+    if (flags & AVSEEK_FLAG_BYTE) {
+        /* use position directly, we will search starting from it */
+        pos = target_ts;
+    } else {
+        /* search for some position with good timestamp match */
+        if(stream_index < 0){
+            stream_index_gen_search = av_find_default_stream_index(s);
+            if (stream_index_gen_search < 0) {
+                ff_restore_parser_state(s, backup);
+                return -1;
+            }
+
+            st = s->streams[stream_index_gen_search];
+            /* timestamp for default must be expressed in AV_TIME_BASE units */
+            ts_adj = av_rescale(target_ts, st->time_base.den, AV_TIME_BASE * (int64_t)st->time_base.num);
+        } else {
+            ts_adj = target_ts;
+            stream_index_gen_search = stream_index;
+        }
+        pos = av_gen_search(s, stream_index_gen_search, ts_adj,
+                            0, INT64_MAX, -1,
+                            AV_NOPTS_VALUE,
+                            AV_NOPTS_VALUE,
+                            flags, &ts_ret, mpegts_get_pcr);
+        if (pos < 0) {
+            ff_restore_parser_state(s, backup);
             return -1;
-//        pid = AV_RB16(buf + 1) & 0x1fff;
-        if(buf[1] & 0x40) break;
-        pos += ts->raw_packet_size;
+        }
     }
-    url_fseek(s->pb, pos, SEEK_SET);
 
+    /* search for actual matching keyframe/starting position for all streams */
+    if (ff_gen_syncpoint_search(s, stream_index, pos, min_ts, target_ts, max_ts, flags) < 0) {
+        ff_restore_parser_state(s, backup);
+        return -1;
+    }
+
+    ff_free_parser_state(s, backup);
     return 0;
 }
 
+static int read_seek(AVFormatContext *s, int stream_index, int64_t target_ts, int flags)
+{
+    int ret;
+    if (flags & AVSEEK_FLAG_BACKWARD) {
+        ret = read_seek2(s, stream_index, INT64_MIN, target_ts, target_ts, flags & ~AVSEEK_FLAG_BACKWARD);
+        if (ret < 0) {
+            // for compatibility reasons, seek to best-fitting timestamp
+            ret = read_seek2(s, stream_index, INT64_MIN, target_ts, INT64_MAX, flags & ~AVSEEK_FLAG_BACKWARD);
+        }
+    } else {
+        ret = read_seek2(s, stream_index, target_ts, target_ts, INT64_MAX, flags);
+        if (ret < 0) {
+            // for compatibility reasons, seek to best-fitting timestamp
+            ret = read_seek2(s, stream_index, INT64_MIN, target_ts, INT64_MAX, flags);
+        }
+    }
+    return ret;
+}
+
 /**************************************************************/
 /* parsing functions - called from other demuxers such as RTP */
 
@@ -1608,6 +1661,7 @@ AVInputFormat mpegts_demuxer = {
     read_seek,
     mpegts_get_pcr,
     .flags = AVFMT_SHOW_IDS|AVFMT_TS_DISCONT,
+    .read_seek2 = read_seek2,
 };
 
 AVInputFormat mpegtsraw_demuxer = {
@@ -1621,4 +1675,5 @@ AVInputFormat mpegtsraw_demuxer = {
     read_seek,
     mpegts_get_pcr,
     .flags = AVFMT_SHOW_IDS|AVFMT_TS_DISCONT,
+    .read_seek2 = read_seek2,
 };
diff --git a/tests/seek.regression.ref b/tests/seek.regression.ref
index 5faf77b069..dc09fa6d4c 100644
--- a/tests/seek.regression.ref
+++ b/tests/seek.regression.ref
@@ -3599,57 +3599,51 @@ ret:-1 st:-1 ts:-0.645825 flags:1
 tests/data/b-lavf.ts
 ret: 0 st: 0 dts:0.660000 pts:0.700000 pos:564 size:24801 flags:1
 ret: 0 st:-1 ts:-1.000000 flags:0
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret: 0 st: 0 dts:0.660000 pts:0.700000 pos:564 size:24801 flags:1
 ret: 0 st:-1 ts:1.894167 flags:1
-ret: 0 st: 0 dts:0.780000 pts:0.820000 pos:65612 size:12623 flags:0
+ret: 0 st: 1 dts:1.457556 pts:1.457556 pos:435596 size:409 flags:1
 ret: 0 st: 0 ts:0.788333 flags:0
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
-ret: 0 st: 0 ts:-0.317500 flags:1
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret: 0 st: 0 dts:1.100000 pts:1.140000 pos:189504 size:12236 flags:0
+ret:-1 st: 0 ts:-0.317500 flags:1
 ret: 0 st: 1 ts:2.576667 flags:0
-ret: 0 st: 0 dts:0.860000 pts:0.900000 pos:96068 size:13086 flags:0
+ret:-5
 ret: 0 st: 1 ts:1.470833 flags:1
-ret: 0 st: 0 dts:0.780000 pts:0.820000 pos:65612 size:12623 flags:0
+ret: 0 st: 0 dts:1.140000 pts:1.180000 pos:203980 size:24787 flags:1
 ret: 0 st:-1 ts:0.365002 flags:0
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
-ret: 0 st:-1 ts:-0.740831 flags:1
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret: 0 st: 0 dts:0.660000 pts:0.700000 pos:564 size:24801 flags:1
+ret:-1 st:-1 ts:-0.740831 flags:1
 ret: 0 st: 0 ts:2.153333 flags:0
-ret: 0 st: 0 dts:0.820000 pts:0.860000 pos:80464 size:13388 flags:0
+ret:-5
 ret: 0 st: 0 ts:1.047500 flags:1
-ret: 0 st: 0 dts:0.740000 pts:0.780000 pos:48316 size:14502 flags:0
+ret: 0 st: 0 dts:0.660000 pts:0.700000 pos:564 size:24801 flags:1
 ret: 0 st: 1 ts:-0.058333 flags:0
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret: 0 st: 0 dts:0.660000 pts:0.700000 pos:564 size:24801 flags:1
 ret: 0 st: 1 ts:2.835833 flags:1
-ret: 0 st: 0 dts:0.900000 pts:0.940000 pos:111296 size:12781 flags:0
+ret: 0 st: 1 dts:1.457556 pts:1.457556 pos:435596 size:409 flags:1
 ret: 0 st:-1 ts:1.730004 flags:0
-ret: 0 st: 0 dts:0.780000 pts:0.820000 pos:65612 size:12623 flags:0
-ret: 0 st:-1 ts:0.624171 flags:1
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret:-5
+ret:-1 st:-1 ts:0.624171 flags:1
 ret: 0 st: 0 ts:-0.481667 flags:0
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret: 0 st: 0 dts:0.660000 pts:0.700000 pos:564 size:24801 flags:1
 ret: 0 st: 0 ts:2.412500 flags:1
-ret: 0 st: 0 dts:0.860000 pts:0.900000 pos:96068 size:13086 flags:0
+ret: 0 st: 1 dts:1.457556 pts:1.457556 pos:435596 size:409 flags:1
 ret: 0 st: 1 ts:1.306667 flags:0
-ret: 0 st: 0 dts:0.740000 pts:0.780000 pos:48316 size:14502 flags:0
-ret: 0 st: 1 ts:0.200844 flags:1
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret: 0 st: 0 dts:1.460000 pts:1.500000 pos:351184 size:12679 flags:0
+ret:-1 st: 1 ts:0.200844 flags:1
 ret: 0 st:-1 ts:-0.904994 flags:0
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret: 0 st: 0 dts:0.660000 pts:0.700000 pos:564 size:24801 flags:1
 ret: 0 st:-1 ts:1.989173 flags:1
-ret: 0 st: 0 dts:0.820000 pts:0.860000 pos:80464 size:13388 flags:0
+ret: 0 st: 1 dts:1.457556 pts:1.457556 pos:435596 size:409 flags:1
 ret: 0 st: 0 ts:0.883344 flags:0
-ret: 0 st: 0 dts:0.740000 pts:0.780000 pos:48316 size:14502 flags:0
-ret: 0 st: 0 ts:-0.222489 flags:1
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret: 0 st: 0 dts:1.100000 pts:1.140000 pos:189504 size:12236 flags:0
+ret:-1 st: 0 ts:-0.222489 flags:1
 ret: 0 st: 1 ts:2.671678 flags:0
-ret: 0 st: 0 dts:0.860000 pts:0.900000 pos:96068 size:13086 flags:0
+ret:-5
 ret: 0 st: 1 ts:1.565844 flags:1
-ret: 0 st: 0 dts:0.780000 pts:0.820000 pos:65612 size:12623 flags:0
+ret: 0 st: 0 dts:1.140000 pts:1.180000 pos:203980 size:24787 flags:1
 ret: 0 st:-1 ts:0.460008 flags:0
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
-ret: 0 st:-1 ts:-0.645825 flags:1
-ret: 0 st: 0 dts:0.700000 pts:0.740000 pos:29140 size:16433 flags:0
+ret: 0 st: 0 dts:0.660000 pts:0.700000 pos:564 size:24801 flags:1
+ret:-1 st:-1 ts:-0.645825 flags:1
 ----------------
 tests/data/b-lavf.ul
 ret: 0 st: 0 dts:0.000000 pts:0.000000 pos:0 size:1024 flags:1