From 3fc55826cad90c650787e31c1726d5fc49b83892 Mon Sep 17 00:00:00 2001
From: Tim Redfern <tim@eclectronics.org>
Date: Thu, 31 Oct 2013 14:05:48 +0000
Subject: audio thumbnails

---
 rotord/src/graph.h | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

(limited to 'rotord/src/graph.h')

diff --git a/rotord/src/graph.h b/rotord/src/graph.h
index 2f8843d..70a7e3a 100644
--- a/rotord/src/graph.h
+++ b/rotord/src/graph.h
@@ -144,6 +144,40 @@ namespace Rotor {
 						return true;
 					}
 				}
+				//fall back to audio
+				libav::audio_decoder loader;
+				if (loader.open(inputfilename)) {
+					Audio_thumbnailer at;
+					at.width=w;
+					at.height=h;
+					int rate = loader.get_sample_rate();
+					int samples = loader.get_number_samples();
+					int channels= loader.get_number_channels();
+					int bits = loader.get_bit_depth();
+					at.init(channels,bits,samples,rate);
+					bool finished=false;
+					uint16_t *audio=new uint16_t[1024*loader.get_number_channels()];
+					uint64_t sample=0;
+					while (loader.get_samples(audio,sample,1024)) {
+						at.process_frame((uint8_t*)audio,1024);
+						sample+=1024;
+					}
+					cv::Mat co=cv::Mat(h,w,CV_8UC3);
+					uchar op;
+					for (int i=0;i<h;i++){
+						uchar* r=co.ptr(i); //pointer to row
+						for (int j=0;j<w;j++){
+							//audio rms in 0..1 range
+							if (at.audiodata[j]>abs(((float)i-h/2)/(h/2))) op=0xFF;
+							else op=0x00;
+							r[j*3]=op/4;
+							r[j*3+1]=op;
+							r[j*3+2]=op/4;
+						}
+					}
+					cv::imwrite(outputfilename.c_str(),co);
+					return true;
+				}
 				return false;
 			}
 		private:
-- 
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