[FFmpeg-devel] Honors -rc_override with libx264

[Etienne Buira]

Hi.

$subject. It might surely be done with -x264opts, but I think a big deal
of ffmpeg is unifying arguments whatever codec is in use.

It has the drawback of not allowing quality factor (is that the same as
crf?), nor q=0 (which should be made possible), nor exploiting setting
local bitrate.
So, would a patch accepting backward compatible -rc_override option as
well as one like <int>,<int>,(q|b|f)=<int> (comments welcome) be welcomed?

Regards.
-------------- next part --------------
diff --git a/libavcodec/libx264.c b/libavcodec/libx264.c
index 519dc51..aa9e4ef 100644
--- a/libavcodec/libx264.c
+++ b/libavcodec/libx264.c
@@ -20,6 +20,7 @@
  */
 
 #include "libavutil/opt.h"
+#include "libavutil/avstring.h"
 #include "avcodec.h"
 #include <x264.h>
 #include <math.h>
@@ -170,6 +171,7 @@ static av_cold int X264_close(AVCodecContext *avctx)
     av_free(x4->level);
     av_free(x4->stats);
     av_free(x4->weightp);
+    av_free(x4->params.rc.psz_zones);
 
     return 0;
 }
@@ -387,6 +389,35 @@ static av_cold int X264_init(AVCodecContext *avctx)
 
     if (avctx->flags & CODEC_FLAG_GLOBAL_HEADER)
         x4->params.b_repeat_headers = 0;
+    
+    if (avctx->rc_override_count) {
+        int i;
+        size_t curlen=1, talen;
+        char strbuf[36], *zones=NULL;
+
+        zones = av_malloc(1);
+        if (!zones)
+            return -1;
+        zones[0] = '\0';
+        for (i=0; i<avctx->rc_override_count; i++) {
+            if (avctx->rc_override[i].qscale == 0) {
+                av_log(avctx, AV_LOG_ERROR, "Quality factor and q=0 rc_override not supported for libx264\n");
+                return -1;
+            }
+
+            talen = snprintf(strbuf, 36, "%s%u,%u,q=%u",
+                             curlen==1 ? "" : "/",
+                             avctx->rc_override[i].start_frame,
+                             avctx->rc_override[i].end_frame,
+                             avctx->rc_override[i].qscale);
+            curlen += talen;
+            zones = av_realloc(zones, curlen);
+            if (!zones)
+                return -1;
+            av_strlcat(zones, strbuf, curlen);
+        }
+        x4->params.rc.psz_zones = zones;
+    }
 
     // update AVCodecContext with x264 parameters
     avctx->has_b_frames = x4->params.i_bframe ?