From 47c4b5c0003fa50cfefc3f2e8a089a9b0feebe3f Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Wed, 4 Dec 2013 20:58:19 +0100
Subject: [PATCH] vd_lavc: factor out libavcodec thread setup

---
 mpvcore/av_common.c    | 19 +++++++++++++++++++
 mpvcore/av_common.h    |  1 +
 video/decode/vd_lavc.c | 16 +---------------
 3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/mpvcore/av_common.c b/mpvcore/av_common.c
index 59f6d636c7..823c825517 100644
--- a/mpvcore/av_common.c
+++ b/mpvcore/av_common.c
@@ -21,10 +21,13 @@
 #include <libavcodec/avcodec.h>
 
 #include "mpvcore/mp_common.h"
+#include "mpvcore/mp_msg.h"
 #include "demux/packet.h"
 #include "av_common.h"
 #include "codecs.h"
 
+#include "osdep/numcores.h"
+
 
 // Copy the codec-related fields from st into avctx. This does not set the
 // codec itself, only codec related header data provided by libavformat.
@@ -114,6 +117,22 @@ void mp_set_av_packet(AVPacket *dst, struct demux_packet *mpkt, AVRational *tb)
     dst->dts = mp_pts_to_av(mpkt ? mpkt->dts : MP_NOPTS_VALUE, tb);
 }
 
+void mp_set_avcodec_threads(AVCodecContext *avctx, int threads)
+{
+    if (threads == 0) {
+        threads = default_thread_count();
+        if (threads < 1) {
+            mp_msg(MSGT_GLOBAL, MSGL_WARN, "Could not determine "
+                   "thread count to use, defaulting to 1.\n");
+            threads = 1;
+        }
+        // Apparently some libavcodec versions have or had trouble with more
+        // than 16 threads, and/or print a warning when using > 16.
+        threads = MPMIN(threads, 16);
+    }
+    avctx->thread_count = threads;
+}
+
 void mp_add_lavc_decoders(struct mp_decoder_list *list, enum AVMediaType type)
 {
     AVCodec *cur = NULL;
diff --git a/mpvcore/av_common.h b/mpvcore/av_common.h
index e457628979..7bf2d64d9e 100644
--- a/mpvcore/av_common.h
+++ b/mpvcore/av_common.h
@@ -31,6 +31,7 @@ void mp_copy_lav_codec_headers(AVCodecContext *avctx, AVCodecContext *st);
 void mp_set_av_packet(AVPacket *dst, struct demux_packet *mpkt, AVRational *tb);
 int64_t mp_pts_to_av(double mp_pts, AVRational *tb);
 double mp_pts_from_av(int64_t av_pts, AVRational *tb);
+void mp_set_avcodec_threads(AVCodecContext *avctx, int threads);
 void mp_add_lavc_decoders(struct mp_decoder_list *list, enum AVMediaType type);
 int mp_codec_to_av_codec_id(const char *codec);
 const char *mp_codec_from_av_codec_id(int codec_id);
diff --git a/video/decode/vd_lavc.c b/video/decode/vd_lavc.c
index b48dc7fce7..10e46b78b1 100644
--- a/video/decode/vd_lavc.c
+++ b/video/decode/vd_lavc.c
@@ -49,7 +49,6 @@
 #include "video/decode/dec_video.h"
 #include "demux/stheader.h"
 #include "demux/packet.h"
-#include "osdep/numcores.h"
 #include "video/csputils.h"
 
 #include "lavc.h"
@@ -393,9 +392,6 @@ static void init_avctx(struct dec_video *vd, const char *decoder,
     avctx->codec_type = AVMEDIA_TYPE_VIDEO;
     avctx->codec_id = lavc_codec->id;
 
-    avctx->thread_count = lavc_param->threads;
-
-
 #if HAVE_AVUTIL_REFCOUNTING
     avctx->refcounted_frames = 1;
     ctx->pic = av_frame_alloc();
@@ -420,17 +416,7 @@ static void init_avctx(struct dec_video *vd, const char *decoder,
             avctx->release_buffer  = mp_codec_release_buffer;
         }
 #endif
-    }
-
-    if (avctx->thread_count == 0) {
-        int threads = default_thread_count();
-        if (threads < 1) {
-            mp_msg(MSGT_DECVIDEO, MSGL_WARN, "[VD_FFMPEG] Could not determine "
-                   "thread count to use, defaulting to 1.\n");
-            threads = 1;
-        }
-        threads = FFMIN(threads, 16);
-        avctx->thread_count = threads;
+        mp_set_avcodec_threads(avctx, lavc_param->threads);
     }
 
     avctx->flags |= lavc_param->bitexact;