From cb09b2ed92594d2d627bc609307f0d693204cde0 Mon Sep 17 00:00:00 2001
From: Philip Gladstone <philipjsg@users.sourceforge.net>
Date: Thu, 30 May 2002 02:38:57 +0000
Subject: [PATCH] * 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 | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/ffmpeg.c b/ffmpeg.c
index e4db82987b..3e7348303d 100644
--- a/ffmpeg.c
+++ b/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;
 
@@ -436,7 +439,8 @@ static void do_video_out(AVFormatContext *s,
     if (nb <= 0) 
         return;
 
-    video_buffer= av_malloc(VIDEO_BUFFER_SIZE);
+    if (!video_buffer)
+        video_buffer= av_malloc(VIDEO_BUFFER_SIZE);
     if(!video_buffer) return;
 
     /* deinterlace : must be done before any resize */
@@ -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')
-            break;
+        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;