vd_lavc: factor out libavcodec thread setup

2 files changed, 20 insertions, 0 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);