[FFmpeg-devel] [PATCH 1/2] add option hls_init_time to set init hls window segment

[Steven Liu]

recover segments duration time by hls_time after init hls window.
This is reuqested by Ibrahim Tachijian

Signed-off-by: LiuQi <liuqi at gosun.com>
---
 libavformat/hlsenc.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index e65f002..f5ceb60 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -85,6 +85,7 @@ typedef struct HLSContext {
     AVFormatContext *vtt_avf;

     float time;            // Set by a private option.
+    float init_time;            // Set by a private option.
     int max_nb_segments;   // Set by a private option.
     int  wrap;             // Set by a private option.
     uint32_t flags;        // enum HLSFlags
@@ -706,7 +707,7 @@ static int hls_write_header(AVFormatContext *s)
     int vtt_basename_size;

     hls->sequence       = hls->start_sequence;
-    hls->recording_time = hls->time * AV_TIME_BASE;
+    hls->recording_time = (hls->init_time ? hls->init_time : hls->time) *
AV_TIME_BASE;
     hls->start_pts      = AV_NOPTS_VALUE;

     if (hls->format_options_str) {
@@ -860,9 +861,19 @@ static int hls_write_packet(AVFormatContext *s,
AVPacket *pkt)
     AVStream *st = s->streams[pkt->stream_index];
     int64_t end_pts = hls->recording_time * hls->number;
     int is_ref_pkt = 1;
+    int init_list_dur = 0;
+    int after_init_list_dur = 0;
     int ret, can_split = 1;
     int stream_index = 0;

+    if (hls->sequence - hls->nb_entries > hls->start_sequence &&
hls->init_time > 0) {
+        /* reset end_pts, hls->recording_time at end of the init hls list
*/
+        init_list_dur = hls->init_time * hls->nb_entries * AV_TIME_BASE;
+        after_init_list_dur = (hls->sequence - hls->nb_entries ) *
hls->time * AV_TIME_BASE;
+        hls->recording_time = hls->time * AV_TIME_BASE;
+        end_pts = init_list_dur + after_init_list_dur ;
+    }
+
     if( st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE ) {
         oc = hls->vtt_avf;
         stream_index = 0;
@@ -972,6 +983,7 @@ static int hls_write_trailer(struct AVFormatContext *s)
 static const AVOption options[] = {
     {"start_number",  "set first number in the sequence",
 OFFSET(start_sequence),AV_OPT_TYPE_INT64,  {.i64 = 0},     0, INT64_MAX,
E},
     {"hls_time",      "set segment length in seconds",
OFFSET(time),    AV_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E},
+    {"hls_init_time", "set segment length in seconds at init list",
    OFFSET(init_time),    AV_OPT_TYPE_FLOAT,  {.dbl = 0},     0, FLT_MAX,
E},
     {"hls_list_size", "set maximum number of playlist entries",
 OFFSET(max_nb_segments),    AV_OPT_TYPE_INT,    {.i64 = 5},     0,
INT_MAX, E},
     {"hls_ts_options","set hls mpegts list of options for the container
format used for hls", OFFSET(format_options_str), AV_OPT_TYPE_STRING, {.str
= NULL},  0, 0,    E},
     {"hls_vtt_options","set hls vtt list of options for the container
format used for hls", OFFSET(vtt_format_options_str), AV_OPT_TYPE_STRING,
{.str = NULL},  0, 0,    E},
--
2.7.4 (Apple Git-66)





Test :

/root/ffmpeg_patched -analyzeduration 1000000 -i udp://MCAST_ADDR:3301 -map
0:0 -map 0:1 -c:v libx264 -preset superfast -g 25 -b:v 900k -maxrate 900k
-bufsize 2000k -filter:v yadif -c:a libfdk_aac -b:a 64k -hls_time 5
*-hls_init_time
1* -hls_list_size 10 -hls_allow_cache 0 -hls_flags delete_segments -f hls
/tmp/playlist.m3u8

The output M3U8 of patched ffmpeg:

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-ALLOW-CACHE:NO
#EXT-X-TARGETDURATION:5
#EXT-X-MEDIA-SEQUENCE:3
#EXTINF:1.000000,
playlist3.ts
#EXTINF:1.000000,
playlist4.ts
#EXTINF:1.000000,
playlist5.ts
#EXTINF:1.000000,
playlist6.ts
#EXTINF:1.000000,
playlist7.ts
#EXTINF:1.000000,
playlist8.ts
#EXTINF:1.600000,
playlist9.ts
#EXTINF:1.000000,
playlist10.ts
#EXTINF:4.000000,
playlist11.ts
#EXTINF:5.000000,
playlist12.ts
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-add-option-hls_init_time-to-set-init-hls-window-segm.patch
Type: application/octet-stream
Size: 3323 bytes
Desc: not available
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20160826/a8ba61c9/attachment.obj>