Fix reading a video using libav (correct API usage)

Author: smvv

bin/tld.c

@@ -24,9 +24,9 @@ int main(int argc, char** argv)
 	AVFormatContext* ic = 0;
 	int video_stream = -1;
 	AVStream* video_st = 0;
-	AVFrame* picture = 0;
-	AVFrame rgb_picture;
-	memset(&rgb_picture, 0, sizeof(AVPicture));
+	AVFrame* picture = avcodec_alloc_frame();
+	AVFrame* rgb_picture = avcodec_alloc_frame();
+	//avcodec_get_frame_defaults(&rgb_picture);
 	AVPacket packet;
 	memset(&packet, 0, sizeof(AVPacket));
 	av_init_packet(&packet);
@@ -47,38 +47,77 @@ int main(int argc, char** argv)
 				continue;
 			video_stream = i;
 			video_st = ic->streams[i];
-			picture = avcodec_alloc_frame();
-			rgb_picture.data[0] = (uint8_t*)ccmalloc(avpicture_get_size(PIX_FMT_RGB24, enc->width, enc->height));
-			avpicture_fill((AVPicture*)&rgb_picture, rgb_picture.data[0], PIX_FMT_RGB24, enc->width, enc->height);
+			avpicture_alloc((AVPicture*) rgb_picture, PIX_FMT_RGB24, enc->width, enc->height);
 			break;
 		}
 	}
 	int got_picture = 0;
 	while (!got_picture)
 	{
+		av_init_packet(&packet);
 		int result = av_read_frame(ic, &packet);
-		if (result == AVERROR(EAGAIN))
+		if (result == AVERROR(EAGAIN) || packet.stream_index != video_stream)
+		{
+			av_free_packet(&packet);
 			continue;
-		avcodec_decode_video2(video_st->codec, picture, &got_picture, &packet);
+		}
+		else if (result < 0)
+			return 1;
+
+		if (avcodec_decode_video2(video_st->codec, picture, &got_picture,
+								 &packet) < 0)
+			return 1;
+		av_free_packet(&packet);
 	}
+
 	ccv_enable_default_cache();
-	struct SwsContext* picture_ctx = sws_getCachedContext(0, video_st->codec->width, video_st->codec->height, video_st->codec->pix_fmt, video_st->codec->width, video_st->codec->height, PIX_FMT_RGB24, SWS_BICUBIC, 0, 0, 0);
-	sws_scale(picture_ctx, (const uint8_t* const*)picture->data, picture->linesize, 0, video_st->codec->height, rgb_picture.data, rgb_picture.linesize);
+
+	struct SwsContext* picture_ctx =
+		sws_getCachedContext(0, video_st->codec->width,
+							 video_st->codec->height, video_st->codec->pix_fmt,
+							 video_st->codec->width, video_st->codec->height,
+							 PIX_FMT_RGB24, SWS_BICUBIC, 0, 0, 0);
+
+	sws_scale(picture_ctx, (const uint8_t* const*) picture->data,
+			  picture->linesize, 0, video_st->codec->height,
+			  rgb_picture->data, rgb_picture->linesize);
+
 	ccv_dense_matrix_t* x = 0;
-	ccv_read(rgb_picture.data[0], &x, CCV_IO_RGB_RAW | CCV_IO_GRAY, video_st->codec->height, video_st->codec->width, rgb_picture.linesize[0]);
+	ccv_read(rgb_picture->data[0], &x, CCV_IO_RGB_RAW | CCV_IO_GRAY,
+			 video_st->codec->height, video_st->codec->width,
+			 rgb_picture->linesize[0]);
 	ccv_tld_t* tld = ccv_tld_new(x, box, ccv_tld_default_params);
+
 	ccv_dense_matrix_t* y = 0;
+
 	for (;;)
 	{
 		got_picture = 0;
+
+		av_init_packet(&packet);
 		int result = av_read_frame(ic, &packet);
-		if (result == AVERROR(EAGAIN))
+
+		if (result == AVERROR(EAGAIN) || packet.stream_index != video_stream)
+		{
+			av_free_packet(&packet);
 			continue;
-		avcodec_decode_video2(video_st->codec, picture, &got_picture, &packet);
+		}
+		else if (result < 0)
+			return 1;
+
+		if (avcodec_decode_video2(video_st->codec, picture, &got_picture,
+								  &packet) < 0)
+			return 1;
+
 		if (!got_picture)
 			break;
-		sws_scale(picture_ctx, (const uint8_t* const*)picture->data, picture->linesize, 0, video_st->codec->height, rgb_picture.data, rgb_picture.linesize);
-		ccv_read(rgb_picture.data[0], &y, CCV_IO_RGB_RAW | CCV_IO_GRAY, video_st->codec->height, video_st->codec->width, rgb_picture.linesize[0]);
+
+		sws_scale(picture_ctx, (const uint8_t* const*)picture->data,
+				  picture->linesize, 0, video_st->codec->height,
+				  rgb_picture->data, rgb_picture->linesize);
+		ccv_read(rgb_picture->data[0], &y, CCV_IO_RGB_RAW | CCV_IO_GRAY,
+				 video_st->codec->height, video_st->codec->width,
+				 rgb_picture->linesize[0]);
 		ccv_tld_info_t info;
 		ccv_comp_t newbox = ccv_tld_track_object(tld, x, y, &info);
 		/*
@@ -132,7 +171,8 @@ int main(int argc, char** argv)
 	}
 	ccv_matrix_free(x);
 	ccv_tld_free(tld);
-	ccfree(rgb_picture.data[0]);
+	avpicture_free((AVPicture *) rgb_picture);
+	av_free(rgb_picture);
 	ccv_disable_cache();
 #endif
 #endif