[FFmpeg-devel] [PATCH 2/2] avcodec/setts_bsf: add an option to set output time base

James Almer jamrial at gmail.com
Mon Feb 28 17:49:06 EET 2022


And a relevant constant to use it in expressions.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 doc/bitstream_filters.texi |  3 +++
 libavcodec/setts_bsf.c     | 11 ++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi
index 87c984185d..b11d357941 100644
--- a/doc/bitstream_filters.texi
+++ b/doc/bitstream_filters.texi
@@ -800,6 +800,9 @@ The next input duration.
 @item TB
 The timebase of stream packet belongs.
 
+ at item TB_OUT
+The output timebase.
+
 @item SR
 The sample rate of stream packet belongs.
 
diff --git a/libavcodec/setts_bsf.c b/libavcodec/setts_bsf.c
index d574449838..e2c1997d0c 100644
--- a/libavcodec/setts_bsf.c
+++ b/libavcodec/setts_bsf.c
@@ -47,7 +47,8 @@ static const char *const var_names[] = {
     "DURATION",    ///< original duration in the file of the frame
     "STARTPTS",    ///< PTS at start of movie
     "STARTDTS",    ///< DTS at start of movie
-    "TB",          ///< timebase of the stream
+    "TB",          ///< input timebase of the stream
+    "TB_OUT",      ///< output timebase of the stream
     "SR",          ///< sample rate of the stream
     "NOPTS",       ///< The AV_NOPTS_VALUE constant
     NULL
@@ -72,6 +73,7 @@ enum var_name {
     VAR_STARTPTS,
     VAR_STARTDTS,
     VAR_TB,
+    VAR_TB_OUT,
     VAR_SR,
     VAR_NOPTS,
     VAR_VARS_NB
@@ -90,6 +92,8 @@ typedef struct SetTSContext {
     int64_t start_pts;
     int64_t start_dts;
 
+    AVRational time_base;
+
     double var_values[VAR_VARS_NB];
 
     AVExpr *ts_expr;
@@ -141,11 +145,15 @@ static int setts_init(AVBSFContext *ctx)
         }
     }
 
+    if (s->time_base.den)
+        ctx->time_base_out = s->time_base;
+
     s->frame_number= 0;
     s->start_pts   = AV_NOPTS_VALUE;
     s->start_dts   = AV_NOPTS_VALUE;
     s->var_values[VAR_NOPTS] = AV_NOPTS_VALUE;
     s->var_values[VAR_TB]    = ctx->time_base_in.den ? av_q2d(ctx->time_base_in) : 0;
+    s->var_values[VAR_TB_OUT]= ctx->time_base_out.den ? av_q2d(ctx->time_base_out) : 0;
     s->var_values[VAR_SR]    = ctx->par_in->sample_rate;
 
     return 0;
@@ -251,6 +259,7 @@ static const AVOption options[] = {
     { "pts", "set expression for packet PTS", OFFSET(pts_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
     { "dts", "set expression for packet DTS", OFFSET(dts_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
     { "duration", "set expression for packet duration", OFFSET(duration_str), AV_OPT_TYPE_STRING, {.str="DURATION"}, 0, 0, FLAGS },
+    { "time_base", "set output timebase", OFFSET(time_base), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, 0, FLAGS },
     { NULL },
 };
 
-- 
2.35.1



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