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4

I'm not sure how it will behave at very low frame rates, but it is worth pointing out this would also limit your options on how and when you could change frames since they would have to follow on the clock cycles. What is more likely to work in this case is a long keyframe interval. The majority of frames in a compression like H.264 only store the changes ...


3

While there are video encoders that do this kind of thing, most commonly this is the work of a video switcher or mixer. A video switcher is a device used for mixing live video from multiple sources. The bad news is they generally aren't cheap. An HD capable switcher is typically in the $6000+ range with the absolute cheapest one I know of being the Black ...


2

I'm sure there are dedicated MP4 encoders out there, maybe someone else has better info. But I've had good results using AVC Ultimate, which takes advantage of CUDA on an NVIDIA card to speed up MP4 processing, to about double the rate I get without it. There's a free version, but I can't remember if the CUDA option is available in that -- I've used the ...


2

Complexity is the main thing. Because of how audio works, there tends to not be a whole lot of variation in the quality you get from a given bit rate. While video often has frames that are very similar from one image to another, audio rarely has the exact same sound playing for a long period of time. This lack of predictability in audio means that the ...


2

Your best bet for high quality and low size is 2 pass variable bit rate, but it is worth noting that the size of the video also has a ton to do with how much motion it contains and how often the scene changes. One of the most popular modern codecs to use for such compression is h.264. Video compression works by looking for similarities not only within one ...


2

There are many hardware options including Intel media SDK, FPGA options, nvidi, ASIC solutions, elgato, etc. But for my money, I prefer quality. The software solutions, especially x264, perform WAY (WAY) better as measured by visual quality by file size ratio. As for Quality per watt in terms of encoding, you cant beat a good ASIC.


2

If compatibility is your top priority, then you should include two alternative versions of your video on your website, like in this HTML example. As for the exact formats I would suggest: H.264 and AAC in MP4: Chrome, Firefox 22+ on Windows, IE9, Safari 3.1 VP8 and Vorbis in WebM: Firefox fallback for Mac and older versions on Windows. (If you need ...


2

Depending how the content was made, the banding might be introduced when you're converting your content from RGB colorspace to YUV. You can try to make an h264 while keeping RGB colorspace, although I've read it's not easy. Are you able to use another codec?


2

The bands you're referring to could well just be a limitation of the 8-bit colour space. In theory the way to solve this is to use 10- or 12-bit colour space through every stage from rendering, to editing and mastering, through to output and even in the screen or projector. However your final output is probably going to be displayed in an 8 bits per ...


2

I'm with AJ. Unless you know the characteristics of every player that might view this, it would be unwise to rely on a small sample of test results. Using a standard frame rate like 24 fps with a keyframe interval of 24 frames will give you essentially the same thing with no compromise in compatibility. The intermediate frames will be minimally small because ...


2

When you ask how something will 'look' you're in the realm of the subjective. Things 'look' different to experienced professionals than they might to the average viewer. But still, the 1080p video will not be as good no matter what you view it on. When you encode at a low bit rate you aren't removing pixels, you're mostly removing high frequencies. Doing ...


2

For CBR encodings, the bitrate is always kept at the bitrate specified regardless of if it is needed. For VBR encoding, the bitrate is an average target, however the media stream will use more or less data rate when it needs to but will try to average to the target. This is why you see 1 pass and 2 pass VBR. 2 pass VBR first makes a pass to estimate where ...


2

To understand this you need to understand how codecs actually work. A plain uncompressed video frame e.g. a single picture is pretty large. I'm talking about a bitmap, not a lossless encoded video, no encoding at all, just plain pixel information. Here simple example of a Full HD frame for some perspective: We have a resolution of 1920x1080 that equals to ...


2

That is way out of the h264 specs. According to Adobe After Effects the format constrains for h264 are at min. 10fps so even 2fps are (not, see below) out of spec and could result in issues with some players. So Avidemux seems to allow out of spec settings, that 1 fps isn't possible, is very likely an internal issue with how h264 gets encoded in Avidemux. ...


2

1) Everytime the GPU has to process something, it will load the necessary data (in that case your video frames) into the VRAM. Simple as that, the GPU cannot work with your system memory. Though the GPU gets it's data from the system memory, so your system memory will act as a buffer and you don't need to load that much data at once into the VRAM. Though ...


2

I have read that the extra ram (4 gb vs 2 gb) might be utilized when you are working with 4k footage, but there are a lot of other factors at play here (cpu / data throughput etc). This is a good article about choosing the right components for your editing pc (including graphics card): ...


2

This isn't a phenomenon, this is compression. It is simply how it works. Compression works by taking an input, runs it through some algorithms and then gets an output that matches up either exactly (lossless) or approximately (lossy) with the original input. It is not stored like normal video data as a set of pixels, but rather some form of data that ...


2

It is hard to say without seeing the file itself, but my best guess is that an issue occurred causing the data stream to die but the meta data was still set "properly". Generally, the actual video data itself is not looked at for the length of the video. Instead, there is header meta data in the file that holds the video stream which indicates how long the ...


1

I haven't seen any difference between 2GB and 4GB. My GTX680 2GB is practically the same as a friend's GTX680 4GB in terms of PP performance. I don't know if this is just on our systems, but even with a fast GPU PP just can't handle more than a couple of filters without dropping frames. It's kind of infuriating, really. My GPU can create beautiful ...


1

You can see the bitrate in this case as a quality target. It will not encode the audio strictly at that bit-rate but try to encode the audio in a way that it will always be "near" your specified bit-rate. Usually you can translate certain bit-rates to a specific quality level which can be compared to lames "V0", "V2" etc. VBR settings, these presets don't ...


1

The output is an .MTS file, which is ~450 MB. What is the reason for that? It is desirable to record and master in the highest quality possible, and only convert to lower bitrates for delivery (if necessary) at the final stage. 450MB for two minutes is 30mbps. That's not particularly high for a capture bitrate; it's a typical capture bitrate for ...


1

HD video is very, very large at high quality. 450MB for two minutes isn't actually that bad. To put it in perspective, assuming you were shooting 1080P and 24fps, if there was no compression applied, that same 2 minutes of video would be 6 gigabytes of information. The reason that videos you download or watch on bluray disks are so much smaller is that ...


1

The best bet is either a slide show player or a variable frame rate video format. Since your image doesn't actually change for large periods of time, formats that normally use a fixed frame rate are not going to produce nearly the quality of results of a VFR format. Handbrake is one option which appears to support using a VFR format.


1

I would recommend the h264 codec as it produces reasonable quality at small size and it provides broad compatibility. The open source encoder x264 is considered as the best one out there. I can't recommend any command line parameters but there are several good programs that make use of the x264 encoder. I like Vidcoder which is a fork of the popular ...


1

Well the program that encoded the file that works was Apple QuickTime so not much of a suprise that it's working. QuickTime can be a little picky when it comes to mpeg4/h264 encoded files. I looked at the files and possible factors are the encoding profile and maybe the GOP setting. Basline Profile Level 3.0 for the broken one and Main Profile Level 3.1 for ...


1

Motion compensation is the use of the motion estimation information to achieve compression. If you can describe the motion, then you only have to describe the changes that occur after compensating for that motion. I used this article as a primer. Basically the first involves how you determine what movement is happening and the other is then used to ...


1

There's a table here showing support for the various video codecs by the four main browsers around today. For Chrome and Safari the only option that plays on both is h.264 in an mp4 container. I've found that main profile h264 video plays best across most modern devices, but you can wind it back to base profile if you're having problems. This is a good ...


1

While this is borderline a product recommendation question, there is an entire class of hardware encoders that support h.264. The cheapest ones I know of are made by Black Magic Design. Matrox also makes some pretty affordable ones. Be aware you are still talking about a $200 - $500+ device for doing the real time encoding though.


1

So Apparently FFMPEG can do this, I had to use -c:v copy and that will leave the video stream intact. I actually used an app called iFFMPEG to figure this out.


1

I know that Virtual Dub can do this, but it only works with a limited number of codecs. Since it's free, it's worth a look to see if it'll do what you want. Otherwise, any demux/remux software will work, but it'll take three steps. First demultiplex the file into video and audio streams, re-encode the audio as needed, then remux them into a combined stream. ...



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