lavc: deprecate the use of AVCodecContext.time_base for decoding

When decoding, this field holds the inverse of the framerate that can be
written in the headers for some codecs. Using a field called 'time_base'
for this is very misleading, as there are no timestamps associated with
it. Furthermore, this field is used for a very different purpose during
encoding.

Add a new field, called 'framerate', to replace the use of time_base for
decoding.

1 files changed, 10 insertions, 1 deletions

diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 8e6c019b62..b79133f981 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -1170,7 +1170,8 @@ typedef struct AVCodecContext {
      * timebase should be 1/framerate and timestamp increments should be
      * identically 1.
      * - encoding: MUST be set by user.
-     * - decoding: Set by libavcodec.
+     * - decoding: the use of this field for decoding is deprecated.
+     *             Use framerate instead.
      */
     AVRational time_base;
 
@@ -2788,6 +2789,14 @@ typedef struct AVCodecContext {
      *             -initial_padding.
      */
     int initial_padding;
+
+    /*
+     * - decoding: For codecs that store a framerate value in the compressed
+     *             bitstream, the decoder may export it here. { 0, 1} when
+     *             unknown.
+     * - encoding: unused
+     */
+    AVRational framerate;
 } AVCodecContext;
 
 /**