Add UI option to configure FFmpeg's video decoder thread count.

External FFmpeg has recently gained multithreaded H.264 decoding
and to make use of this feature, it is necessary to inform FFmpeg
about the maximum number of threads it may use for decoding.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/libffmpeg/ff_video_decoder.c b/src/libffmpeg/ff_video_decoder.c
index 077ff2fad..9ab4f9daf 100644
--- a/src/libffmpeg/ff_video_decoder.c
+++ b/src/libffmpeg/ff_video_decoder.c
@@ -67,6 +67,7 @@ typedef struct ff_video_class_s {
   video_decoder_class_t   decoder_class;
 
   int                     pp_quality;
+  int                     thread_count;
   
   xine_t                 *xine;
 } ff_video_class_t;
@@ -368,6 +369,12 @@ static void init_video_codec (ff_video_decoder_t *this, unsigned int codec_type)
     _x_stream_info_set(this->stream, XINE_STREAM_INFO_VIDEO_HANDLED, 0);
     return;
   }
+
+  if (this->class->thread_count > 1) {
+    avcodec_thread_init(this->context, this->class->thread_count);
+    this->context->thread_count = this->class->thread_count;
+  }
+
   pthread_mutex_unlock(&ffmpeg_lock);
 
   lprintf("lavc decoder opened\n");
@@ -422,6 +429,12 @@ static void init_video_codec (ff_video_decoder_t *this, unsigned int codec_type)
 
 }
 
+static void thread_count_cb(void *user_data, xine_cfg_entry_t *entry) {
+  ff_video_class_t   *class = (ff_video_class_t *) user_data;
+  
+  class->thread_count = entry->num_value;
+}
+
 static void pp_quality_cb(void *user_data, xine_cfg_entry_t *entry) {
   ff_video_class_t   *class = (ff_video_class_t *) user_data;
   
@@ -1530,6 +1543,15 @@ void *init_video_plugin (xine_t *xine, void *data) {
       "too much."),
     10, pp_quality_cb, this);
   
+  this->thread_count = xine->config->register_num(config, "video.processing.ffmpeg_thread_count", 1, 
+    _("FFmpeg video decoding thread count"),
+    _("You can adjust the number of video decoding threads which FFmpeg may use.\n"
+      "Higher values should speed up decoding but it depends on the codec used "
+      "whether parallel decoding is supported. A rule of thumb is to have one "
+      "decoding thread per logical CPU (typically 1 to 4). A change will take "
+      "effect with playing the next stream."),
+    10, thread_count_cb, this);
+
   return this;
 }