WAV and soft-boiled eggs - Revision history

PhilippeTeuwen: /* Making-of */

2015-03-04T09:50:51Z

Making-of

← Older revision		Revision as of 09:50, 4 March 2015
Line 27:		Line 27:
	Its spectrogram:		Its spectrogram:
	<br>[[File:Tribute_rogers_stamos_spectrogram_orig.png\|600px]]		<br>[[File:Tribute_rogers_stamos_spectrogram_orig.png\|600px]]
	<br>Even if the video contained a 44kHz audio, we see that the original source was only 22kHz. It looks like we've plenty of room to draw but remember that whatever you put below 18-~~19kHz~~ can be heard so we can only use the very high frequencies.		<br>Even if the video contained a 44kHz audio, we see that the original source was only 22kHz. It looks like we've plenty of room to draw but remember that whatever you put below 18-20kHz (depending on people and their age...) can be heard so we can only use the very high frequencies.
	<br><br>I prepared a simple banner in Gimp, with text in grey on black background. Grey means reduced audio signal, less chance for it to be audible.		<br><br>I prepared a simple banner in Gimp, with text in grey on black background. Grey means reduced audio signal, less chance for it to be audible.
	<br><br>[[File:Tribute_rogers_stamos_you_cant.png]]		<br><br>[[File:Tribute_rogers_stamos_you_cant.png]]

PhilippeTeuwen: /* Making-of */

2015-03-04T09:49:58Z

Making-of

← Older revision		Revision as of 09:49, 4 March 2015
Line 27:		Line 27:
	Its spectrogram:		Its spectrogram:
	<br>[[File:Tribute_rogers_stamos_spectrogram_orig.png\|600px]]		<br>[[File:Tribute_rogers_stamos_spectrogram_orig.png\|600px]]
			<br>Even if the video contained a 44kHz audio, we see that the original source was only 22kHz. It looks like we've plenty of room to draw but remember that whatever you put below 18-19kHz can be heard so we can only use the very high frequencies.
	<br><br>I prepared a simple banner in Gimp, with text in grey on black background. Grey means reduced audio signal, less chance for it to be audible.		<br><br>I prepared a simple banner in Gimp, with text in grey on black background. Grey means reduced audio signal, less chance for it to be audible.
	<br><br>[[File:Tribute_rogers_stamos_you_cant.png]]		<br><br>[[File:Tribute_rogers_stamos_you_cant.png]]

PhilippeTeuwen: /* Making-of */

2015-03-04T09:46:08Z

Making-of

← Older revision		Revision as of 09:46, 4 March 2015
Line 37:		Line 37:
	AudioPaint always generates stereo files but we used only the left channel, so we need to isolate it:		AudioPaint always generates stereo files but we used only the left channel, so we need to isolate it:
	sox Tribute_rogers_stamos_you_cant.wav -c 1 Tribute_rogers_stamos_you_cant1.wav remix 1		sox Tribute_rogers_stamos_you_cant.wav -c 1 Tribute_rogers_stamos_you_cant1.wav remix 1
	Here is ~~it's~~ spectrogram:		Here is its spectrogram:
	<br>[[File:Tribute_rogers_stamos_spectrogram_msg.png\|600px]]		<br>[[File:Tribute_rogers_stamos_spectrogram_msg.png\|600px]]
	<br><br>Now we can merge the interview WAV with the high frequencies one and code it over 32 bits:		<br><br>Now we can merge the interview WAV with the high frequencies one and code it over 32 bits:

PhilippeTeuwen: /* Example */

2015-03-04T09:45:54Z

Example

← Older revision		Revision as of 09:45, 4 March 2015
Line 7:		Line 7:
	<br>Sound quality is not great but that's from the original source, not due to our manipulations.		<br>Sound quality is not great but that's from the original source, not due to our manipulations.

	Let's display ~~it's~~ spectrogram and discover a first easter-egg:		Let's display its spectrogram and discover a first easter-egg:
	sox Tribute_rogers_stamos.wav -n spectrogram		sox Tribute_rogers_stamos.wav -n spectrogram
	[[File:Tribute_rogers_stamos_spectrogram1.png\|600px]]		[[File:Tribute_rogers_stamos_spectrogram1.png\|600px]]

PhilippeTeuwen: /* Making-of */

2015-03-04T09:45:40Z

Making-of

← Older revision		Revision as of 09:45, 4 March 2015
Line 25:		Line 25:
	I made it mono, 44kHz, 16-bit signed and I normalized it:		I made it mono, 44kHz, 16-bit signed and I normalized it:
	sox interview.wav -r 44100 -c 1 -e signed -b 16 interview16.wav norm		sox interview.wav -r 44100 -c 1 -e signed -b 16 interview16.wav norm
	~~It's~~ spectrogram:		Its spectrogram:
	<br>[[File:Tribute_rogers_stamos_spectrogram_orig.png\|600px]]		<br>[[File:Tribute_rogers_stamos_spectrogram_orig.png\|600px]]
	<br><br>I prepared a simple banner in Gimp, with text in grey on black background. Grey means reduced audio signal, less chance for it to be audible.		<br><br>I prepared a simple banner in Gimp, with text in grey on black background. Grey means reduced audio signal, less chance for it to be audible.

PhilippeTeuwen: /* Example */

2015-03-04T01:07:31Z

Example

← Older revision		Revision as of 01:07, 4 March 2015
Line 7:		Line 7:
	<br>Sound quality is not great but that's from the original source, not due to our manipulations.		<br>Sound quality is not great but that's from the original source, not due to our manipulations.

	Let's display it's spectrogram:		Let's display it's spectrogram and discover a first easter-egg:
	sox Tribute_rogers_stamos.wav -n spectrogram		sox Tribute_rogers_stamos.wav -n spectrogram
	[[File:Tribute_rogers_stamos_spectrogram1.png\|600px]]		[[File:Tribute_rogers_stamos_spectrogram1.png\|600px]]

PhilippeTeuwen at 01:06, 4 March 2015

2015-03-04T01:06:50Z

← Older revision		Revision as of 01:06, 4 March 2015
Line 1:		Line 1:
	==Intro==		=Intro=
	We've seen in [[BMP_PCM_polyglot]] that we can merge a BMP and a WAV in a single file.		We've seen in [[BMP_PCM_polyglot]] that we can merge a BMP and a WAV in a single file.
	<br>Here we will merge two 16-bit WAV files in a single 32-bit file.		<br>Here we will merge two 16-bit WAV files in a single 32-bit file.
	<br>Depending how you interpret the endianness of the file you'll hear one or the other WAV, considering that with a maximal dynamic range of about 96dB (16-bit resolution), whatever below that level cannot be heard.		<br>Depending how you interpret the endianness of the file you'll hear one or the other WAV, considering that with a maximal dynamic range of about 96dB (16-bit resolution), whatever below that level cannot be heard.
	==Example==		=Example=
	[http://wiki.yobi.be/images/4/4a/Tribute_rogers_stamos.wav Tribute_rogers_stamos.wav] is such a WAV.		[http://wiki.yobi.be/images/4/4a/Tribute_rogers_stamos.wav Tribute_rogers_stamos.wav] is such a WAV.
	<br>Sound quality is not great but that's from the original source, not due to our manipulations.		<br>Sound quality is not great but that's from the original source, not due to our manipulations.
Line 18:		Line 18:
	[[File:Tribute_rogers_stamos_spectrogram2.png\|600px]]		[[File:Tribute_rogers_stamos_spectrogram2.png\|600px]]

	==Making-of==		=Making-of=
	I used a short sequence featured in a TV news I found on Youtube about [http://justsecurity.org/20304/transcript-nsa-director-mike-rogers-vs-yahoo-encryption-doors/ NSA Director Mike Rogers vs. Yahoo! on Encryption Back Doors]:		I used a short sequence featured in a TV news I found on Youtube about [http://justsecurity.org/20304/transcript-nsa-director-mike-rogers-vs-yahoo-encryption-doors/ NSA Director Mike Rogers vs. Yahoo! on Encryption Back Doors]:
	youtube-dl "https://www.youtube.com/watch?v=s5GN1heBRLg"		youtube-dl "https://www.youtube.com/watch?v=s5GN1heBRLg"
Line 70:		Line 70:
	wavout.write(header+outdata)		wavout.write(header+outdata)
	</source>		</source>
			And voilà!

PhilippeTeuwen at 01:05, 4 March 2015

2015-03-04T01:05:36Z

@@ Line 1: / Line 1: @@
 ==Intro==
 We've seen in [[BMP_PCM_polyglot]] that we can merge a BMP and a WAV in a single file.
-<br>Here we will merge two WAV files.
+<br>Here we will merge two 16-bit WAV files in a single 32-bit file.

PhilippeTeuwen: Created page with "==Intro== We've seen in BMP_PCM_polyglot that we can merge a BMP and a WAV in a single file.
Here we will merge two WAV files."

2015-03-03T10:57:01Z

Created page with "==Intro== We've seen in BMP_PCM_polyglot that we can merge a BMP and a WAV in a single file. <br>Here we will merge two WAV files."

New page

==Intro==
We've seen in [[BMP_PCM_polyglot]] that we can merge a BMP and a WAV in a single file.
<br>Here we will merge two WAV files.

WAV and soft-boiled eggs - Revision history

PhilippeTeuwen: /* Making-of */

PhilippeTeuwen: /* Making-of */

PhilippeTeuwen: /* Making-of */

PhilippeTeuwen: /* Example */

PhilippeTeuwen: /* Making-of */

PhilippeTeuwen: /* Example */

PhilippeTeuwen at 01:06, 4 March 2015

PhilippeTeuwen at 01:05, 4 March 2015

PhilippeTeuwen: Created page with "==Intro== We've seen in BMP_PCM_polyglot that we can merge a BMP and a WAV in a single file. Here we will merge two WAV files."

PhilippeTeuwen: Created page with "==Intro== We've seen in BMP_PCM_polyglot that we can merge a BMP and a WAV in a single file.
Here we will merge two WAV files."