Composite video signal over earphone terminal

Question

SAZAR 0 Junior Poster in Training

15 Years Ago

Made an experiment:
1. connected SONY camera's composite out to computer audio line-in
2. recorded incoming audio/video signal as sound using SoundForge program (stereo recording - one recorded audio (can clearly hear it), the other channel is video (hear as noise)); saved as WAV file
3. copied WAV file onto MP4 player
4. used composite audio/video cable (came with SONY camera), connected it to stereo audio output of MP4 player - connected it to TV

Results:
- heard audio signal (nothing special)
- picture on TV was just some noise (experiment failed)

-------

What went wrong here? How come picture didn't show?
How can it be made work?

---------------------------

Idea for this interesting little experiment came to me when I thought about if it is possible to make a program for Pocket PCs (Smartphone) which don't have TV out to emulate audio/video signal using Pocket PCs earphone terminal.

Can such program be made?

3 Contributors
4 Replies
294 Views
6 Years Discussion Span
Latest Post 8 Years Ago Latest Post by bournep

Reply to this topic

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.

SAZAR 0 Junior Poster in Training · Answer 1 · 2009-02-28T03:11:20+00:00

SAZAR 0 Junior Poster in Training

15 Years Ago

...What? This issue is not interesting for you?

SAZAR 0 Junior Poster in Training · Answer 2 · 2009-03-29T02:19:02+00:00

SAZAR 0 Junior Poster in Training

15 Years Ago

...I don't believe it. No one answered yet...

gegrove 0 Newbie Poster · Answer 3 · 2009-07-01T06:26:35+00:00

Made an experiment:
1. connected SONY camera's composite out to computer audio line-in
2. recorded incoming audio/video signal as sound using SoundForge program (stereo recording - one recorded audio (can clearly hear it), the other channel is video (hear as noise)); saved as WAV file
3. copied WAV file onto MP4 player
4. used composite audio/video cable (came with SONY camera), connected it to stereo audio output of MP4 player - connected it to TV
Results:
- heard audio signal (nothing special)
- picture on TV was just some noise (experiment failed)
-------
What went wrong here? How come picture didn't show?
How can it be made work?
---------------------------
Idea for this interesting little experiment came to me when I thought about if it is possible to make a program for Pocket PCs (Smartphone) which don't have TV out to emulate audio/video signal using Pocket PCs earphone terminal.
Can such program be made?

I need something like this but from a Scope I can see the video wave Form so how do I convert this to AVI the output is has only X And Y values

bournep 0 Newbie Poster · Answer 4 · 2016-02-11T17:00:48+00:00

I admire your curiosity and experimentation! However, the video signal has a much higher bandwidth than audio. Most domestic sound cards will record audio up to about 20 kHz - this is limited by the sample rate, which is normally 44.1 kHz. The sound card will filter off anything above 20 kHz to prevent aliasing. In contrast a standard definition composite video signal has a bandwidth of about 5.5 MHz. Crucially the synchronisation pulses that the TV needs to display the picture have a duration of just 4.7 micro seconds so with such a low sampling rate on the sound card, these are essentially removed. Similarly the output from a phone can only go up to about 20 kHz so cannot generate a video signal - sorry!