Add average frame calculation.

2 files changed, 50 insertions, 167 deletions

diff --git a/src/Makefile b/src/Makefile
index 0cd8c91..b5a6901 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,11 +1,10 @@
 CFLAGS=-std=c99 -Wall -Wstrict-prototypes -Wmissing-prototypes -Wno-unused-parameter
-LibAV=`pkg-config --cflags --libs libavcodec`
 LIBAV_DECODE_FLAGS=`pkg-config --libs --cflags libavformat libavcodec libavutil libswscale`
 
 all: advtime decode_frame frame_to_pgm
 
-advtime: advtime.c
-	gcc ${LibAV} advtime.c -o $@
+advtime: advtime.c video_decode.c
+	gcc $(CFLAGS) $(LIBAV_DECODE_FLAGS) advtime.c video_decode.c -o $@
 
 decode_frame: decode_frame.c
 	gcc $(CFLAGS) $(LIBAV_DECODE_FLAGS) decode_frame.c -o $@
diff --git a/src/advtime.c b/src/advtime.c
index e4efb34..07be68c 100644
--- a/src/advtime.c
+++ b/src/advtime.c
@@ -1,182 +1,66 @@
-/**
- * @file
- * libavcodec API use example.
- *
- * @example libavcodec/api-example.c
- * Note that this library only handles codecs (mpeg, mpeg4, etc...),
- * not file formats (avi, vob, etc...). See library 'libavformat' for the
- * format handling
- */
-
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
-
-#ifdef HAVE_AV_CONFIG_H
-#undef HAVE_AV_CONFIG_H
-#endif
-
-#include <libavcodec/avcodec.h>
-#include <libavutil/audioconvert.h>
-#include <libavutil/common.h>
-#include <libavutil/imgutils.h>
-#include <libavutil/mathematics.h>
-#include <libavutil/samplefmt.h>
-
-#define INBUF_SIZE 4096
-#define AUDIO_INBUF_SIZE 20480
-#define AUDIO_REFILL_THRESH 4096
+#include <stdint.h>
 
-/*
- * Video decoding example
- */
+#include "video_decode.h"
 
-static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize,
-                     char *filename)
+static void
+pgm_save(unsigned char *buf, int wrap, int xsize, int ysize, char *filename)
 {
-    FILE *f;
-    int i;
-
-    f=fopen(filename,"w");
-    fprintf(f,"P5\n%d %d\n%d\n",xsize,ysize,255);
-    for(i=0;i<ysize;i++)
-        fwrite(buf + i * wrap,1,xsize,f);
-    fclose(f);
+	FILE *f;
+	int i;
+
+	f = fopen(filename, "w");
+	fprintf(f, "P5\n%d %d\n%d\n", xsize, ysize, 255);
+	for(i=0; i < ysize; i++)
+		fwrite(buf + i * wrap, 1, xsize, f);
+	fclose(f);
 }
 
-static void video_decode_example(const char *outfilename, const char *filename)
+int64_t
+frame_average(struct video_frame *frame)
 {
-    AVCodec *codec;
-    AVCodecContext *c= NULL;
-    int frame, got_picture, len;
-    FILE *f;
-    AVFrame *picture;
-    uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
-    char buf[1024];
-    AVPacket avpkt;
-
-    av_init_packet(&avpkt);
-
-    /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */
-    memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE);
-
-    printf("Video decoding\n");
-
-    /* find the mpeg1 video decoder */
-    codec = avcodec_find_decoder(CODEC_ID_MPEG1VIDEO);
-    if (!codec) {
-        fprintf(stderr, "codec not found\n");
-        exit(1);
-    }
-
-    c = avcodec_alloc_context3(codec);
-    picture= avcodec_alloc_frame();
-
-    if(codec->capabilities&CODEC_CAP_TRUNCATED)
-        c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */
-
-    /* For some codecs, such as msmpeg4 and mpeg4, width and height
-       MUST be initialized there because this information is not
-       available in the bitstream. */
-
-    /* open it */
-    if (avcodec_open2(c, codec, NULL) < 0) {
-        fprintf(stderr, "could not open codec\n");
-        exit(1);
-    }
-
-    /* the codec gives us the frame size, in samples */
-
-    f = fopen(filename, "rb");
-    if (!f) {
-        fprintf(stderr, "could not open %s\n", filename);
-        exit(1);
-    }
-
-    frame = 0;
-    for(;;) {
-        avpkt.size = fread(inbuf, 1, INBUF_SIZE, f);
-        if (avpkt.size == 0)
-            break;
-
-        /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio)
-           and this is the only method to use them because you cannot
-           know the compressed data size before analysing it.
-
-           BUT some other codecs (msmpeg4, mpeg4) are inherently frame
-           based, so you must call them with all the data for one
-           frame exactly. You must also initialize 'width' and
-           'height' before initializing them. */
-
-        /* NOTE2: some codecs allow the raw parameters (frame size,
-           sample rate) to be changed at any frame. We handle this, so
-           you should also take care of it */
-
-        /* here, we use a stream based decoder (mpeg1video), so we
-           feed decoder and see if it could decode a frame */
-        avpkt.data = inbuf;
-        while (avpkt.size > 0) {
-            len = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
-            if (len < 0) {
-                fprintf(stderr, "Error while decoding frame %d\n", frame);
-                exit(1);
-            }
-            if (got_picture) {
-                printf("saving frame %3d\n", frame);
-                fflush(stdout);
-
-                /* the picture is allocated by the decoder. no need to
-                   free it */
-                snprintf(buf, sizeof(buf), outfilename, frame);
-                pgm_save(picture->data[0], picture->linesize[0],
-                         c->width, c->height, buf);
-                frame++;
-            }
-            avpkt.size -= len;
-            avpkt.data += len;
-        }
-    }
-
-    /* some codecs, such as MPEG, transmit the I and P frame with a
-       latency of one frame. You must do the following to have a
-       chance to get the last frame of the video */
-    avpkt.data = NULL;
-    avpkt.size = 0;
-    len = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
-    if (got_picture) {
-        printf("saving last frame %3d\n", frame);
-        fflush(stdout);
-
-        /* the picture is allocated by the decoder. no need to
-           free it */
-        snprintf(buf, sizeof(buf), outfilename, frame);
-        pgm_save(picture->data[0], picture->linesize[0],
-                 c->width, c->height, buf);
-        frame++;
-    }
-
-    fclose(f);
-
-    avcodec_close(c);
-    av_free(c);
-//    avcodec_free_frame(&picture);
-    printf("\n");
+	int64_t average = 0;
+	uint8_t *row = frame->data;
+	uint8_t *col = NULL;
+
+	for (int y = 0; y < frame->height; ++y) {
+		col = row;
+		for (int x = 0; x < frame->width; ++x) {
+			average += *col;
+			col++;
+		}
+		row += frame->stride;
+	}
+
+	return average / (frame->width * frame->height);
 }
 
-int main(int argc, char **argv)
+int
+main(int argc, char **argv)
 {
+	struct video_decode *vd;
+	struct video_frame *frame;
+	int ret;
+	int64_t timestamp = 0;
+
 	if (argc < 2)
 		return 1;
 
-	/* register all the codecs */
-	avcodec_register_all();
+	if (argc == 3 && strtol(argv[2], NULL, 10) > 0)
+		timestamp = strtol(argv[2], NULL, 10);
+
+	ret = video_decode_init(&vd, argv[1], timestamp);
+	if (ret < 0)
+		return -ret;
 
-//	FILE *fh = fopen(argv[1], "rb");
-//	if (fh == NULL)
-//		return 1;
+	while (video_decode_get_frame(vd, &frame) == 0) {
+		printf("%d\n", frame_average(frame));
+		video_decode_free_frame(&frame);
+	}
 
-	video_decode_example("out", argv[1]);
+//	pgm_save(frame->data, frame->stride, frame->width, frame->height,
+//		 argv[2]);
 
-//	fclose(sh);
-	return 0;
+	video_decode_uninit(&vd);
 }