From 7de3460728c06c5ee182bd20070dd58cfc801cbe Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Tue, 9 Dec 2014 13:18:15 -0500
Subject: [PATCH] count audio and video frames and show some statistics

---
 Makefile |  4 ++--
 hello.c  | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 7243bb4..a557540 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 TARGET := hello
 OBJS := hello.o
-CFLAGS := $$(pkg-config --cflags libavformat) -Wall
-LDFLAGS := $$(pkg-config --libs libavformat)
+CFLAGS := $$(pkg-config --cflags libavformat libavcodec) -Wall
+LDFLAGS := $$(pkg-config --libs libavformat libavcodec)
 
 all: $(TARGET)
 
diff --git a/hello.c b/hello.c
index bf57d04..6ec7f52 100644
--- a/hello.c
+++ b/hello.c
@@ -25,6 +25,47 @@ int main(int argc, char * argv[])
 
     av_dump_format(context, 0, argv[1], 0);
 
+    int video_stream_idx = av_find_best_stream(context, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);
+    printf("Video stream index: %d\n", video_stream_idx);
+    int audio_stream_idx = av_find_best_stream(context, AVMEDIA_TYPE_AUDIO, -1, -1, NULL, 0);
+    printf("Audio stream index: %d\n", audio_stream_idx);
+
+    AVPacket pkt;
+    av_init_packet(&pkt);
+
+    int n_total_frames = 0;
+    int n_video_frames = 0;
+    int n_audio_frames = 0;
+    int max_video_size = 0;
+    int total_video_size = 0;
+    int max_audio_size = 0;
+    int total_audio_size = 0;
+    while (av_read_frame(context, &pkt) >= 0)
+    {
+        n_total_frames++;
+        if (pkt.stream_index == video_stream_idx)
+        {
+            n_video_frames++;
+            total_video_size += pkt.size;
+            if (pkt.size > max_video_size)
+                max_video_size = pkt.size;
+        }
+        if (pkt.stream_index == audio_stream_idx)
+        {
+            n_audio_frames++;
+            total_audio_size += pkt.size;
+            if (pkt.size > max_audio_size)
+                max_audio_size = pkt.size;
+        }
+    }
+    printf("Saw %d frames: %d video and %d audio (%d other)\n",
+           n_total_frames, n_video_frames, n_audio_frames,
+           n_total_frames - n_video_frames - n_audio_frames);
+    printf("Video size: %d, max: %d, average: %d\n",
+           total_video_size, max_video_size, total_video_size / n_video_frames);
+    printf("Audio size: %d, max: %d, average: %d\n",
+           total_audio_size, max_audio_size, total_audio_size / n_audio_frames);
+
     avformat_close_input(&context);
 
     return 0;