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I have a requirement where I need to enable playback (full screen) of a h.264 MPEG4 (thanks for the correction!) video from a local network, launchable from a browser link on a Windows workstation, and be frame accurate.
By frame accurate I mean that I need to be able to scrub through the video in the same way you would with a vtr, stop at a frame, and then move backwards and forwards frame by frame (it is for a very specific compliance requirement where have to be able to check every frame if there is something that is potentially against broadcasting guidelines).
The application itself is used to capture notes while viewing the material, so the end model is for a dual monitor workstation, with a web form in one, the video playing full screen in the second (no issue launching the video and manually having to move it to the second screen), and then the user controls the video via keyboard shortcuts or a jog shuttle.
I have looked at QT, but the java bindings seem to be dead or nearly so, flash isn't frame accurate, VLC given its streaming heritage seems to be only able to move forward by a frame and not backwards, and all I have left are commercial offerings that in my experience are difficult and expensive to change.
Any ideas of where I should look or alternative options? Any advice appreciated!
An alternative would be on the server side, dumping each frame out as an image, and then just stepping through the video via images rather than trying to get a video player to work frame by frame.
Here's an ffmpeg command line to dump frames out of a video, to get you started:
ffmpeg -i video.mpeg -f image2 frames/frame-%03d.jpeg
If you wanted to get fancy, you could try using a video player for playing the video, and then when you stop and want to step by frames, replace it with a frame-by-frame view implemented using images. This would take a bit more work to convert video times to frame numbers when you pause the video, but may give you what you need.
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For example, how would a washing machine play a specific sound (MP3 or WAV or whatever) when finished? Which external components are needed?
I know this is a really vague question but I could not find any real solutions except some kind of MP3 player module which seems to be more "end-user friendly" instead of being used programmatically (skip and pause buttons).
Various beeps can be made simply by toggling a pin, but I assume your are looking for something more melodious, and without using a sound synthesiser.
For short sound bites: you can store them in (external) memory and play them through a DAC, if your MCU has one. I put a basic implementation of this for SAMD21G-based Arduinos here; the idea is the same for all MCUs that have a DAC. If your MCU doesn't have a DAC, you can use an external one, or make a "poor man's DAC" by using PWM and low-pass filtering the output.
Another option is creating an I2S stream from stored samples and send them to an external amplifier (module) that accepts I2S. It helps when your MCU has an I2S peripheral.
For longer sounds, your best bet is probably playing them from a MCU-controlled MP3-player, because you need the SD-card storage or a similarly large storage anyway for large sound files.
In all cases, you'll need an external amplifier and speaker.
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I apologize if there is a better place to post this. I recently came across a couple CVS single-use video cameras that I had been using back in 2005. I still have the USB cable I made and now that I've switched to Mac I can use Puretool to extract the old videos from the cameras. The problem I'm having is that I can only hear the audio when viewing the videos with VLC media player. I read on PureTools site, a common problem is that the audio codec used is incompatible with Quicktime and the audio stream needs to be converted. There is a link on their site to a program called FixSound which is purported to fix this, but the link is dead and I've been unable to find any further information about this. If anyone could point me in the right direction, I'd be very grateful. All the videos I'm dealing with are from the first year of my son's life and I'd really like to be able to archive them in a more uniform format. I would think this would be possible to do using Adobe Audition or some other program in Adobe's CS6 Master Collection but I've only dealt with Photoshop, Illustrator, Dreamweaver, Flash & Fireworks. I have no experience with audio or video yet.
Thanks,
Mark
I found a workaround but if anyone has a better suggestion, please post.
I used SoundConverter / GStreamer on my Ubuntu box to convert the audio from the old video to mp3 then combined that with the original video on my iMac using Encore and built it as .f4v (for achiving, I can just build a DVD from Encore). I guess from there I can use Media Encoder to come up with a Quicktime, 3gp, etc... version.
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Need to find if there is a open source project for audio signal processing, just as we have openCV for image processing.
Thanks
In my course for the more technical part, we were introduced to signal processing, we had to use Octave with the audio package and gnu plot for plotting.
For the fun part of the course used MaxMSP/Jitter which is a commercial project,
but there's always PureData which is opensource and the Jitter equivalent would be PD Gem, but just for audio signal processing you should be fine with PureData.
In short, if you're into the number crunching bit, Octave should be fine.
We also did the image processing in Octave too, it's two dimensions as opposed to one(sound), but it's still signal processing. You can apply a high-pass or a low pass filter to an image too, you can try an echo/delay on images for fun if you like.
Pure Data is a bit different, since you patch cords instead of typing lots of code, but it's pretty fun and one of the advantages is that you can make changes live, while your patch/program is running which makes it great for fast prototyping.
Straying a bit from audio signal processing, if you're into generative music, you should have a look at some opensource projects like ChucK, SuperCollider, ixi
or fluxus...some do cool stuff with Haskell.
Update
On the c++ side you can also check out Dr. Mick Grierson's Maximilian library which also includes a nice little addon for OpenFrameworks
It's also worth checking out Sonic Visualiser and Vamp Plugins (a lot of nice goodies there)
HTH
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Does anyone know a great audio and video file compressor?
I currenting compressing wmv to 3gp with AVS software.
when i compress the file its out 250kb and that only about 2mins and 30 sec of video.
i would like to compress the sound and video smaller so that i can add more time to my video.
FFmpeg is probably the best choice. It has a wide-range of formats, flexibility and codec support. There's little comparison. There are a variety of desktop apps that are built on it too, if you need a UI.
if you are looking for an application super (c) is very good at all sort of video compressions tho it has a pretty weird UI
I'm a huge fan of ffmpeg. Find out what codec and resolution your mobile device wants. If you're lucky, H.264 will be supported. That codec seems to produce excellent compression these days.
Crazy thing I found the other day. I used QuickTime to File->Export->iPhone my 250MB .avi file and it output the file into four new/different files. Three were in .m4v format and varied in size from 62.3MB to 6.8MB. However the fourth file was a .mov file that was only 381 bytes in size. You read that right. It compressed the video from 250MB to 381b or <1KB. If my math serves me right that is over 600K times smaller than the original file.
Just fyi. Hope this helps.
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I'm looking for (linux) command line tools that can help with video editing. I am mostly interested in:
Cutting
Transitions
Effects
Any pointers would be appreciated (I know ffmpeg can do basic cutting, but not much beyond that afaik).
Two tools I use are transcode and mencoder.
Transcode is a suite of command line
utilities for transcoding video and
audio codecs, and for converting
beween different container formats.
A variety of video and audio pre and
post-processing filters are available,
including (but not limited to):
framerate conversion
smoothing
cutting
MEncoder is a free command line video decoding, encoding and filtering tool based on mplayer.
Avisynth under WINE is your best bet. You can use ffmpeg or mencoder to do the actual encoding, and avisynth .avs files for the actual editing. You may have to use mencoder under WINE to access the avs files as well. I haven't tried this myself, but it should work, barring any WINE issues.
If this is part of some production app, if there's any way you can farm the work out to an actual windows computer you'll save yourself a lot of pain.
If you want to get your hands dirty you could try using the gstreamer and Gnonlin to make your own CLI video app. You can actually use a language like Ruby to call gstreamer from, so you don't have to use C.