Merge pull request #477 from jasaw/tune-h264-encode-quality

Tune h264_omx encode video quality
Motion-Project · Sep 17, 2017 · 924ec9f · 924ec9f
2 parents 8863857 + 86166cf
commit 924ec9f
Showing 1 changed file with 19 additions and 10 deletions.
diff --git a/ffmpeg.c b/ffmpeg.c
@@ -466,21 +466,30 @@ static int ffmpeg_set_pts(struct ffmpeg *ffmpeg, const struct timeval *tv1){
 
 static int ffmpeg_set_quality(struct ffmpeg *ffmpeg){
 
-    char crf[4];
-
     ffmpeg->opts = 0;
     if (ffmpeg->vbr > 100) ffmpeg->vbr = 100;
     if (ffmpeg->ctx_codec->codec_id == MY_CODEC_ID_H264 ||
         ffmpeg->ctx_codec->codec_id == MY_CODEC_ID_HEVC){
-        if (ffmpeg->vbr > 0) {
-            ffmpeg->vbr = (int)(( (100-ffmpeg->vbr) * 51)/100);
+        if (ffmpeg->vbr <= 0)
+            ffmpeg->vbr = 45; // default to 45% quality
+        av_dict_set(&ffmpeg->opts, "preset", "ultrafast", 0);
+        av_dict_set(&ffmpeg->opts, "tune", "zerolatency", 0);
+        if ((strcmp(ffmpeg->codec->name, "h264_omx") == 0) || (strcmp(ffmpeg->codec->name, "mpeg4_omx") == 0)) {
+            // H264 OMX encoder quality can only be controlled via bit_rate
+            // bit_rate = ffmpeg->width * ffmpeg->height * ffmpeg->fps * quality_factor
+            ffmpeg->vbr = (ffmpeg->width * ffmpeg->height * ffmpeg->fps * ffmpeg->vbr) >> 7;
+            // Clip bit rate to min
+            if (ffmpeg->vbr < 4000) // magic number
+                ffmpeg->vbr = 4000;
+            ffmpeg->ctx_codec->profile = FF_PROFILE_H264_HIGH;
+            ffmpeg->ctx_codec->bit_rate = ffmpeg->vbr;
         } else {
-            ffmpeg->vbr = 28;
+            // Control other H264 encoders quality via CRF
+            char crf[4];
+            ffmpeg->vbr = (int)(( (100-ffmpeg->vbr) * 51)/100);
+            snprintf(crf, 4, "%d", ffmpeg->vbr);
+            av_dict_set(&ffmpeg->opts, "crf", crf, 0);
         }
-       snprintf(crf, 4, "%d",ffmpeg->vbr);
-       av_dict_set(&ffmpeg->opts, "preset", "ultrafast", 0);
-       av_dict_set(&ffmpeg->opts, "tune", "zerolatency", 0);
-       av_dict_set(&ffmpeg->opts, "crf", crf, 0);
     } else {
         /* The selection of 8000 in the else is a subjective number based upon viewing output files */
         if (ffmpeg->vbr > 0){
@@ -489,7 +498,7 @@ static int ffmpeg_set_quality(struct ffmpeg *ffmpeg){
             ffmpeg->ctx_codec->global_quality=ffmpeg->vbr;
         }
     }
-    MOTION_LOG(INF, TYPE_ENCODER, NO_ERRNO, "vbr/crf for codec: %d", ffmpeg->vbr);
+    MOTION_LOG(INF, TYPE_ENCODER, NO_ERRNO, "%s codec vbr/crf/bit_rate: %d", ffmpeg->codec->name, ffmpeg->vbr);
 
     return 0;
 }