* Go faster stripes: don't check to see if the user presses 'q' if stdin

  returns EOF -- e.g. it is connected to /dev/null
* Make the 1MB video buffer only allocated once rather than on each frame.
  The allocation and deallocation causes significant performance loss as the
  kernel remaps the address space each time.

Originally committed as revision 629 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffmpeg.c

@@ -207,8 +207,11 @@ static int read_key(void)
     tv.tv_usec = 0;
     n = select(1, &rfds, NULL, NULL, &tv);
     if (n > 0) {
-        if (read(0, &ch, 1) == 1)
+        n = read(0, &ch, 1);
+        if (n == 1)
             return ch;
+
+        return n;
     }
     return -1;
 }
@@ -226,7 +229,7 @@ static void term_init(void)
 
 static int read_key(void)
 {
-    return -1;
+    return 0;
 }
 
 #endif
@@ -417,7 +420,7 @@ static void do_video_out(AVFormatContext *s,
     int n1, n2, nb, i, ret, frame_number, dec_frame_rate;
     AVPicture *picture, *picture2, *pict;
     AVPicture picture_tmp1, picture_tmp2;
-    UINT8 *video_buffer;
+    static UINT8 *video_buffer;
     UINT8 *buf = NULL, *buf1 = NULL;
     AVCodecContext *enc, *dec;
 
@@ -436,6 +439,7 @@ static void do_video_out(AVFormatContext *s,
     if (nb <= 0) 
         return;
 
+    if (!video_buffer)
         video_buffer= av_malloc(VIDEO_BUFFER_SIZE);
     if(!video_buffer) return;
 
@@ -521,7 +525,6 @@ static void do_video_out(AVFormatContext *s,
     the_end:
     av_free(buf);
     av_free(buf1);
-    av_free(video_buffer);
 }
 
 static void do_video_stats(AVOutputStream *ost, 
@@ -597,6 +600,7 @@ static int av_encode(AVFormatContext **output_files,
     INT64 min_pts, start_time;
     AVInputFile *file_table;
     AVFormatContext *stream_no_data;
+    int key;
 
     file_table= (AVInputFile*) av_mallocz(nb_input_files * sizeof(AVInputFile));
     if (!file_table)
@@ -884,6 +888,7 @@ static int av_encode(AVFormatContext **output_files,
     start_time = gettime();
     min_pts = 0;
     stream_no_data = 0;
+    key = -1;
 
     for(;;) {
         int file_index, ist_index;
@@ -897,8 +902,12 @@ static int av_encode(AVFormatContext **output_files,
 
     redo:
         /* if 'q' pressed, exits */
-        if (read_key() == 'q')
+        if (key) {
+            /* read_key() returns 0 on EOF */
+            key = read_key();
+            if (key == 'q')
                 break;
+        }
 
         /* select the input file with the smallest pts */
         file_index = -1;