[FFmpeg-devel] [PATCH] lavf/segment: add -segment_delta option

[Stefano Sabatini]

FIXME: bump micro version
---
 doc/muxers.texi       |   11 +++++++++++
 libavformat/segment.c |   13 +++++++++++++
 2 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/doc/muxers.texi b/doc/muxers.texi
index c63356a..2f7d572 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -452,6 +452,17 @@ segment start and end time expressed in seconds.
 The segment muxer supports the following options:
 
 @table @option
+ at item segment_delta @var{delta}
+Specify the accuracy in seconds when selecting the start time for a
+segment. Default value is 0.
+
+This is especially useful with video segments, which are split at GOP
+boundaries. When delta is specified a given key-frame is selected if
+its PTS satisfies the relation:
+ at example
+PTS >= start_time - delta
+ at end example
+
 @item segment_format @var{format}
 Override the inner container format, by default it is guessed by the filename
 extension.
diff --git a/libavformat/segment.c b/libavformat/segment.c
index 54b9f9a..4f145d4 100644
--- a/libavformat/segment.c
+++ b/libavformat/segment.c
@@ -43,6 +43,8 @@ typedef struct {
     int64_t time;          ///< segment duration
     char *times_str;       ///< segment times specification string
     int64_t *times;        ///< list of segment interval specification
+    char *delta_str;       ///< approximation value duration used for the segment times
+    int64_t delta;
     int nb_times;          ///< number of elments in the times array
     int has_video;
     double start_time, end_time;
@@ -195,6 +197,15 @@ static int seg_write_header(AVFormatContext *s)
         }
     }
 
+    if (seg->delta_str) {
+        if ((ret = av_parse_time(&seg->delta, seg->delta_str, 1)) < 0) {
+            av_log(s, AV_LOG_ERROR,
+                   "Invalid time duration specification '%s' for delta option\n",
+                   seg->delta_str);
+            return ret;
+        }
+    }
+
     oc = avformat_alloc_context();
 
     if (!oc)
@@ -315,6 +326,7 @@ static int seg_write_trailer(struct AVFormatContext *s)
 
     av_opt_free(seg);
     av_freep(&seg->times);
+    av_freep(&seg->delta_str);
 
     oc->streams = NULL;
     oc->nb_streams = 0;
@@ -325,6 +337,7 @@ static int seg_write_trailer(struct AVFormatContext *s)
 #define OFFSET(x) offsetof(SegmentContext, x)
 #define E AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
+    { "segment_delta",     "set approximation value used for the segment times", OFFSET(delta_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
     { "segment_format",    "set container format used for the segments", OFFSET(format),  AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
     { "segment_time",      "set segment duration",                       OFFSET(time_str), AV_OPT_TYPE_STRING,{.str = NULL},  0, 0,       E },
     { "segment_times",     "set segment split time points",              OFFSET(times_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0,      E },
-- 
1.7.5.4