Changeset 6260 in orxonox.OLD for branches/avi_play/src/lib/graphics/importer

Timestamp:

Dec 22, 2005, 5:08:39 PM (19 years ago)

Author:

hdavid

Message:

branches\avi_play: MediaContainer::getFrame(int frame_number) works

Location:

branches/avi_play/src/lib/graphics/importer

Files:

• media_container.cc (modified) (4 diffs)
• media_container.h (modified) (1 diff)

branches/avi_play/src/lib/graphics/importer/media_container.cc

@@ -75 +75 @@
 }
 
-SDL_Surface* MediaContainer::getFrame(float time_stamp)
-{
-  if (time_stamp != AV_NOPTS_VALUE)
+SDL_Surface* MediaContainer::getFrame(int frame_number)
+{
+  // seek doesnt work for the first two frames
+  // you will get ugly fragments
+  if(frame_number < 2)
+    return this->getNextFrame();
+  else
   {
-    /* add the stream start time */
-    //time_stamp += AV_NOPTS_VALUE;
-    //PRINTF(1)("starttime %f\n", format_context->start_time);
-    //time_stamp += format_context->start_time;
-    int err = av_seek_frame(format_context, video_stream, time_stamp, AVSEEK_FLAG_BACKWARD);
-    if (err < 0)
-    {
-      PRINTF(1)("could not seek to position %f\n", time_stamp);
-      return NULL;
-    }
-
+    // seeks to the nearest keyframe
+    // NOTE: there is only about every 5s a keyframe!
+    av_seek_frame(format_context, video_stream, frame_number, AVSEEK_FLAG_BACKWARD);
+    
+    // go from the keyframe to the exact position
+    codec_context->hurry_up = 1;
+    do {
+      av_read_frame(format_context, &packet);
+      if(packet.pts >= frame_number-1)
+        break;
+      int frame_finished;
+      avcodec_decode_video(codec_context, frame, &frame_finished, packet.data, packet.size);
+      av_free_packet(&packet);
+    } while(1);
+    codec_context->hurry_up = 0;
+  
     return this->getNextFrame();
   }
-
-  return this->getNextFrame();
 }
 
@@ -114 +121 @@
       if(frame_finished)
       {
-        //PRINTF(1)("frame_number: %i\n", this->getFrameNumber());
+        PRINTF(1)("frame_number: %i\n", this->getFrameNumber());
         // Conversion from YUV to RGB
         // Most codecs return images in YUV 420 format
@@ -128 +135 @@
         data = new uint8_t[codec_context->width*codec_context->height*3*sizeof(uint8_t)];
         for(int i = 0; i < codec_context->height; i++)
-          memcpy(&data[i*codec_context->width*3], picture->data[0]+i * picture->linesize[0],codec_context->width*sizeof(uint8_t)*3);
+          memcpy(&data[i*codec_context->width*3], picture->data[0]+i *
+                 picture->linesize[0],codec_context->width*sizeof(uint8_t)*3);
 
         surface = SDL_CreateRGBSurfaceFrom(data, codec_context->width,
@@ -285 +293 @@
   PRINTF(1)("nb_frames: %i\n", format_context->streams[video_stream]->nb_frames);
   PRINTF(1)("r_frame_rate: %i\n", format_context->streams[video_stream]->r_frame_rate.num);
-  PRINTF(1)("FPS: %f\n", av_q2d(format_context->streams[video_stream]->r_frame_rate));
+  PRINTF(1)("fps: %0.2f\n", av_q2d(format_context->streams[video_stream]->r_frame_rate));
   PRINTF(1)("========================\n");
   PRINTF(1)("=    AVCodecContext    =\n");

branches/avi_play/src/lib/graphics/importer/media_container.h

@@ -52 +52 @@
   ~MediaContainer();
 
-  SDL_Surface* getFrame(float time_stamp);
+  SDL_Surface* getFrame(int frame_number);
   SDL_Surface* getNextFrame();
   vector<SDL_Surface*> getFrameList();