[FFmpeg-devel] [PATCH v2 04/12] lavc/videotoolboxenc: Add entropy setting

Rick Kern kernrj at gmail.com
Fri Apr 22 18:14:06 CEST 2016


Add an entropy setting to choose between CAVLC and CABAC.

Signed-off-by: Rick Kern <kernrj at gmail.com>
---
 libavcodec/videotoolboxenc.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
index ec69bb1..07577b6 100644
--- a/libavcodec/videotoolboxenc.c
+++ b/libavcodec/videotoolboxenc.c
@@ -41,6 +41,12 @@ typedef enum VT_H264Profile {
     H264_PROF_COUNT
 } VT_H264Profile;
 
+typedef enum VTH264Entropy{
+    VT_ENTROPY_NOT_SET,
+    VT_CAVLC,
+    VT_CABAC
+} VTH264Entropy;
+
 static const uint8_t start_code[] = { 0, 0, 0, 1 };
 
 typedef struct BufNode {
@@ -69,6 +75,7 @@ typedef struct VTEncContext {
 
     int64_t profile;
     int64_t level;
+    int64_t entropy;
 
 #if !TARGET_OS_IPHONE
     int64_t allow_sw;
@@ -627,6 +634,11 @@ static av_cold int vtenc_init(AVCodecContext *avctx)
         vtctx->has_b_frames = false;
     }
 
+    if (vtctx->entropy == VT_CABAC && vtctx->profile == H264_PROF_BASELINE) {
+        av_log(avctx, AV_LOG_WARNING, "CABAC entropy requires 'main' or 'high' profile, but baseline was requested. Encode will not use CABAC entropy.\n");
+        vtctx->entropy = VT_ENTROPY_NOT_SET;
+    }
+
     if (!get_vt_profile_level(avctx, &profile_level)) return AVERROR(EINVAL);
 
     vtctx->session = NULL;
@@ -736,6 +748,21 @@ static av_cold int vtenc_init(AVCodecContext *avctx)
         }
     }
 
+    if (vtctx->entropy != VT_ENTROPY_NOT_SET) {
+        CFStringRef entropy = vtctx->entropy == VT_CABAC ?
+                                kVTH264EntropyMode_CABAC:
+                                kVTH264EntropyMode_CAVLC;
+
+        status = VTSessionSetProperty(vtctx->session,
+                                      kVTCompressionPropertyKey_H264EntropyMode,
+                                      entropy);
+
+        if (status) {
+            av_log(avctx, AV_LOG_ERROR, "Error setting entropy property: %d\n", status);
+            return AVERROR_EXTERNAL;
+        }
+    }
+
     status = VTCompressionSessionPrepareToEncodeFrames(vtctx->session);
     if (status) {
         av_log(avctx, AV_LOG_ERROR, "Error: cannot prepare encoder: %d\n", status);
@@ -1484,6 +1511,10 @@ static const AVOption options[] = {
         { .i64 = -1 }, -1, 1, VE },
 #endif
 
+    { "entropy", "Entropy coding", OFFSET(entropy), AV_OPT_TYPE_INT, { .i64 = VT_ENTROPY_NOT_SET }, VT_ENTROPY_NOT_SET, VT_CABAC, VE, "entropy" },
+    { "cavlc", "CAVLC entropy coding", 0, AV_OPT_TYPE_CONST, { .i64 = VT_CAVLC }, INT_MIN, INT_MAX, VE, "entropy" },
+    { "cabac", "CABAC entropy coding", 0, AV_OPT_TYPE_CONST, { .i64 = VT_CABAC }, INT_MIN, INT_MAX, VE, "entropy" },
+
     { NULL },
 };
 
-- 
2.7.4



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