[FFmpeg-devel] [PATCH 1/6] lavc: Add device context field to AVCodecContext

[Mark Thompson]

For use by codec implementations which require a device to operation
but will allocate frames internally.
---
The following patches make use of it for qsv.  Is this definition appropriate to solve the issues with cuvid device setup as well?


 doc/APIchanges       |  3 +++
 libavcodec/avcodec.h | 38 ++++++++++++++++++++++++++++++++++++--
 libavcodec/utils.c   |  1 +
 libavcodec/version.h |  2 +-
 4 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/doc/APIchanges b/doc/APIchanges
index c0ed711..d1d9a14 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,9 @@ libavutil:     2015-08-28
 
 API changes, most recent first:
 
+2017-xx-xx - xxxxxxx - lavc 57.74.100- avcodec.h
+  Add AVCodecContext.hw_device_ctx.
+
 2017-01-12 - xxxxxxx - lavfi 6.69.100- buffersink.h
   Add av_buffersink_get_*() functions.
 
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 4d26d14..9758bb8 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -3532,8 +3532,13 @@ typedef struct AVCodecContext {
 
     /**
      * A reference to the AVHWFramesContext describing the input (for encoding)
-     * or output (decoding) frames. The reference is set by the caller and
-     * afterwards owned (and freed) by libavcodec.
+     * or output (decoding) frames which will be used by a hardware codec.
+     *
+     * It can be set by the user if they wish to supply the frames used, or it
+     * can be set automatically by libavcodec for decoding when get_format()
+     * indicates that it should output hardware frames.
+     *
+     * If set by the user:
      *
      * - decoding: This field should be set by the caller from the get_format()
      *             callback. The previous reference (if any) will always be
@@ -3550,6 +3555,20 @@ typedef struct AVCodecContext {
      *             AVCodecContext.pix_fmt.
      *
      *             This field should be set before avcodec_open2() is called.
+     *
+     * If set by libavcodec:
+     *
+     * - decoding: The hw_device_ctx field should be set by the user before
+     *             calling avcodec_open2().  If at some later point a hardware
+     *             pixel format is selected by get_format(), then a new
+     *             AVHWFramesContext will be created by the decoder and put
+     *             in this field.
+     *
+     *             It will be valid when get_buffer2() is called (which must
+     *             then return a buffer from the given context).
+     *
+     * - encoding: Unused.  In this case the user must not supply hardware
+     *             frames to the encoder.
      */
     AVBufferRef *hw_frames_ctx;
 
@@ -3583,6 +3602,21 @@ typedef struct AVCodecContext {
      */
     int64_t max_pixels;
 
+    /**
+     * A reference to the AVHWDeviceContext describing the device which will
+     * be used by a hardware encoder/decoder.  The reference is set by the
+     * caller and afterwards owned (and freed) by libavcodec.
+     *
+     * This should only be used if either the codec device does not require
+     * hardware frames or any that are used are allocated internally by
+     * libavcodec.  If the frames may be supplied by the user, then
+     * hw_frames_ctx must be used instead.
+     *
+     * If a device is to be supplied, this field should be set before
+     * avcodec_open2() is called.
+     */
+    AVBufferRef *hw_device_ctx;
+
 } AVCodecContext;
 
 AVRational av_codec_get_pkt_timebase         (const AVCodecContext *avctx);
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 1263306..0d1f87e 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -3060,6 +3060,7 @@ av_cold int avcodec_close(AVCodecContext *avctx)
     avctx->nb_coded_side_data = 0;
 
     av_buffer_unref(&avctx->hw_frames_ctx);
+    av_buffer_unref(&avctx->hw_device_ctx);
 
     if (avctx->priv_data && avctx->codec && avctx->codec->priv_class)
         av_opt_free(avctx->priv_data);
diff --git a/libavcodec/version.h b/libavcodec/version.h
index b0dd46d..33b3bcb 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,7 +28,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR  57
-#define LIBAVCODEC_VERSION_MINOR  73
+#define LIBAVCODEC_VERSION_MINOR  74
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
-- 
2.7.4