[FFmpeg-devel] [PATCH V2 1/2] avformat movenc extend video_track_timescale flag range to allow use of video stream timescale for track

[vectronic]

Extend range of video_track_timescale flag value to -1 to indicate video stream timescale should be used for track timebase. Add debug message if video_track_timescale is not specified and the video stream timescale is clamped to greater than 10000.

Signed-off-by: vectronic <hello.vectronic at gmail.com>
---
 libavformat/movenc.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 32e8109268..bcc0ab4377 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -92,7 +92,7 @@ static const AVOption options[] = {
     { "min_frag_duration", "Minimum fragment duration", offsetof(MOVMuxContext, min_fragment_duration), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
     { "frag_size", "Maximum fragment size", offsetof(MOVMuxContext, max_fragment_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
     { "ism_lookahead", "Number of lookahead entries for ISM files", offsetof(MOVMuxContext, ism_lookahead), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
-    { "video_track_timescale", "set timescale of all video tracks", offsetof(MOVMuxContext, video_track_timescale), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
+    { "video_track_timescale", "set timescale of all video tracks, -1 to use existing stream timescale", offsetof(MOVMuxContext, video_track_timescale), AV_OPT_TYPE_INT, {.i64 = 0}, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
     { "brand",    "Override major brand", offsetof(MOVMuxContext, major_brand),   AV_OPT_TYPE_STRING, {.str = NULL}, .flags = AV_OPT_FLAG_ENCODING_PARAM },
     { "use_editlist", "use edit list", offsetof(MOVMuxContext, use_editlist), AV_OPT_TYPE_BOOL, {.i64 = -1}, -1, 1, AV_OPT_FLAG_ENCODING_PARAM},
     { "fragment_index", "Fragment number of the next fragment", offsetof(MOVMuxContext, fragments), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
@@ -6454,14 +6454,19 @@ static int mov_init(AVFormatContext *s)
                 }
                 track->height = track->tag >> 24 == 'n' ? 486 : 576;
             }
-            if (mov->video_track_timescale) {
+            if (mov->video_track_timescale > 0) {
                 track->timescale = mov->video_track_timescale;
                 if (mov->mode == MODE_ISM && mov->video_track_timescale != 10000000)
                     av_log(s, AV_LOG_WARNING, "Warning: some tools, like mp4split, assume a timescale of 10000000 for ISMV.\n");
             } else {
                 track->timescale = st->time_base.den;
+                if (mov->video_track_timescale != -1) {
                 while(track->timescale < 10000)
                     track->timescale *= 2;
+                if (track->timescale != st->time_base.den)
+                    av_log(s, AV_LOG_DEBUG, "Stream timescale was low (%d), the track timescale has been forced to %d.\n"
+                                            "Specify -video_track_timescale -1 to prevent this.\n", st->time_base.den, track->timescale);
+                }
             }
             if (st->codecpar->width > 65535 || st->codecpar->height > 65535) {
                 av_log(s, AV_LOG_ERROR, "Resolution %dx%d too large for mov/mp4\n", st->codecpar->width, st->codecpar->height);
-- 
2.24.2 (Apple Git-127)