[FFmpeg-devel] [PATCH] avutil/frame: use bitfields for some boolean and enum fields

James Almer jamrial at gmail.com
Mon Apr 17 17:39:30 EEST 2023


Should reduce the size of AVFrame in the next major bump without changing the API.

Suggested-by: Anton Khirnov <anton at khirnov.net>
Signed-off-by: James Almer <jamrial at gmail.com>
---
This supersedes "avutil/frame: add new interlaced and top_field_first flags"
and "avutil/frame: add a keyframe flag to AVFrame".

 libavutil/frame.h   | 56 +++++++++++++++++++++++++++++++++++++++++++++
 libavutil/version.h |  1 +
 2 files changed, 57 insertions(+)

diff --git a/libavutil/frame.h b/libavutil/frame.h
index f85d630c5c..c26067f383 100644
--- a/libavutil/frame.h
+++ b/libavutil/frame.h
@@ -416,6 +416,7 @@ typedef struct AVFrame {
      */
     int format;
 
+#if FF_API_BITFIELDS
     /**
      * 1 -> keyframe, 0-> not
      */
@@ -425,6 +426,57 @@ typedef struct AVFrame {
      * Picture type of the frame.
      */
     enum AVPictureType pict_type;
+#else
+    /**
+     * 1 -> keyframe, 0-> not
+     */
+    unsigned int key_frame: 1;
+
+    /**
+     * The content of the picture is interlaced.
+     */
+    unsigned int interlaced_frame: 1;
+
+    /**
+     * If the content is interlaced, is top field displayed first.
+     */
+    unsigned int top_field_first: 1;
+
+    /**
+     * Tell user application that palette has changed from previous frame.
+     */
+    unsigned int palette_has_changed: 1;
+
+    /**
+     * Reserved. Must not be touched.
+     */
+    unsigned int reserved_bitfield: (sizeof(unsigned int) * 8) - 9;
+
+    /**
+     * MPEG vs JPEG YUV range.
+     * - encoding: Set by user
+     * - decoding: Set by libavcodec
+     */
+    enum AVColorRange color_range: 2;
+
+    enum AVChromaLocation chroma_location: 3;
+
+    /**
+     * Picture type of the frame.
+     */
+    enum AVPictureType pict_type: 8;
+
+    enum AVColorPrimaries color_primaries: 8;
+
+    enum AVColorTransferCharacteristic color_trc: 8;
+
+    /**
+     * YUV colorspace type.
+     * - encoding: Set by user
+     * - decoding: Set by libavcodec
+     */
+    enum AVColorSpace colorspace: 8;
+#endif
 
     /**
      * Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
@@ -491,6 +543,7 @@ typedef struct AVFrame {
      */
     int repeat_pict;
 
+#if FF_API_BITFIELDS
     /**
      * The content of the picture is interlaced.
      */
@@ -505,6 +558,7 @@ typedef struct AVFrame {
      * Tell user application that palette has changed from previous frame.
      */
     int palette_has_changed;
+#endif
 
 #if FF_API_REORDERED_OPAQUE
     /**
@@ -595,6 +649,7 @@ typedef struct AVFrame {
      */
     int flags;
 
+#if FF_API_BITFIELDS
     /**
      * MPEG vs JPEG YUV range.
      * - encoding: Set by user
@@ -614,6 +669,7 @@ typedef struct AVFrame {
     enum AVColorSpace colorspace;
 
     enum AVChromaLocation chroma_location;
+#endif
 
     /**
      * frame timestamp estimated using various heuristics, in stream time base
diff --git a/libavutil/version.h b/libavutil/version.h
index 40f92af055..23cad31b46 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -115,6 +115,7 @@
 #define FF_API_FRAME_PICTURE_NUMBER     (LIBAVUTIL_VERSION_MAJOR < 59)
 #define FF_API_HDR_VIVID_THREE_SPLINE   (LIBAVUTIL_VERSION_MAJOR < 59)
 #define FF_API_FRAME_PKT                (LIBAVUTIL_VERSION_MAJOR < 59)
+#define FF_API_BITFIELDS                (LIBAVUTIL_VERSION_MAJOR < 59)
 
 /**
  * @}
-- 
2.40.0



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