Tag Info

Hot answers tagged

4

Hope this explanation is what you're looking for: When you transcode to an encoding such as H.264 (MPEG-4 part 10) you necessarily also resample the video, that's part of H.264 compression technique. Nontheless, I doubt if this is the reason you experience a timing gap since the resampling doesn't necessarily influence the clock rate of the media. So, I ...


4

The default settings for ffmpeg are very low quality, and since you don't specify any codec or quality parameters it's just using the defaults (I don't know why the devs don't fix that because it generates a lot of questions on forums everywhere). Try adding -c:v libx264 -crf 20 -preset slow to the command. -c:v libx264 tells it to use the libx264 ...


3

One big loss in converting VHS to DVD arises from going through the composite domain. Both VHS and MPEG2 use a separated chroma paradigm -- on the VHS tape are two signals, essentially luma and bandwidth-limited chroma. MPEG2 (the standard for DVD) also uses separate luma and chroma. But the standard output from a VHS player combines the signals in a way ...


3

A lot of these answers seem somewhat misleading unfortunately. Forget about getting a capture card. Practically every one has AGC. AGC is very similar to macrovision, except it's superimposed onto any video source. It's impossible to disable unless you use Linux and know your way around hacking drivers. Some cards on Windows have third party tools to ...


2

Assuming DVD quality would be enough, you may consider archiving 720p mpeg-4 files with a bitrate of 2 Mbits, which would equate roughly to 1 hour = 1 GB data. That would mean 27,000 hours = 27,000 GB = 27 Terabytes. So you need to consider a 50 TB storage system (including redundancy and overhead) and a tape backup system as well (LTO-6 has an uncompressed ...


2

There are lots of things to consider before committing to an operation of this size, but there is also an imperative to act quickly. Given that it's SP Betacam and Umatic the tapes are probably beginning to reach the end of their playable life. In a decade they may all be paperweights. A good place to start is the U.S. Federal Agencies Digitization ...


2

An MP4 file normally contains H.264 video and AAC audio, both of which are compatible with the FLV container. You could simply copy over the streams: ffmpeg -i input.mp4 -c copy output.flv Since you're copying the streams, this will be as close to instantaneous as you're going to get and will not result in any loss of quality.


2

Under the video tab, you'll see two options. Video Codec, which is how the video is encoded (h.264 is the standard for .mp4 files), and Quality, which controls the level of video compression that occurs. It's the Quality slider that you're mostly worried about if you want to keep it an mp4. Drag that slider to the right to improve the quality (this will ...


2

Given your are using a VPS this is no suprise (guessing you only have a single core with 1-3GHz) and you won't be able to crunch the conversion down to a few minutes. You can try using -c:v libx264 -presets ultrafast but I'd guess it will still take you about 45-60 minutes to encode. Also remove the -crf option when using a preset (they choose a default ...


2

I can't give you specific commands but since these are fairly short I'd extract the individual frames into a TIFF stack (or similar), then import them at the correct (7fps) frame rate into your editor. Then I would apply twixtor or an open-source equivalent to raise the frame rate. How well those work depends somewhat on the amount of motion. 7 fps to 30 fps ...


2

They came in as .ogg?? I thought you converted to dvd? Are you talking about then ripping the DVD video with HandBrake or something? Also, you're doing something wrong, or at least have your file extension -> "open with" settings screwed up if renaming a .ogg to a .mp4 is necessary. Maybe it opens with a different player then, and only the player ...


1

The best way to conserve the VHS's would be to scan each frame in at the highest quality possible and export to a video file, this would be a very long process and would require some expensive kit or a professional service. If they are historical value and you want the best it would be worth spending the money and getting it done by a pro but that cost is ...


1

If you are looking something that can do that at the same time and is reasonably well developed, then you are probably looking at avconv. It has the same base as ffmpeg, which has already been mentioned, but currently doesn't have a GUI (to the best of my knowledge, i've not gone looking, since i have no need for it). Let's look at an example of how you ...


1

The only way to do it with literally zero mathematical quality loss is to make a gigantic output file with a lossless codec. (e.g. utvideo, FFV1, or x264 in lossless mode (--qp 0). A better solutions that would achieve the same thing is: mux the subtitle file into the mkv, with mkvmerge. You set a flag so it either plays by default or doesn't. Then you'd ...


1

Thanks for posting -v debug output. From that, I see the colormatrix filter doesn't support high-bit-depth inputs. There's an auto-inserted scale filter downsampling to yuv422p (which means 8bit), before it. You might as well compress the output with an 8-bit-per-component codec, if you need ffmpeg's colormatrix anyway, since ffmpeg already downsampled ...


1

This did it for me: avidemux --nogui --load 1.png `for i in {2..15}; do echo "--append $i.png"; done` --no-audio --fps 5 --video-codec Xvid --save-ogm out.ogm --quit I only tried with 15 images, but you can increase the total number if you want. For whatever reason for me it messed up colours a little bit, and i was unable to save into AVI, but hopefully ...


1

Use ffmpeg instead, e.g. ffmpeg audio.mp4 -framerate 50 -pattern_type glob -i 3_DucksTakeOff_720p50_CgrLevels_SINC_FILTER_SVTdec05_/'*'.sgi -sws_flags lanczos+print_info -c:a copy -c:v libx264 -preset slow -crf 22 -pix_fmt yuv420p output.mkv adjust the input file naming as necessary. ffmpeg can read png just fine. If there are other PNGs in the same dir ...


1

I'm not sure why they are not lining up, perhaps there is some problem with the audio track near the beginning that is causing truncation at the start. Unless you have meaningful information there, my suggestion would be to remove the silence at the end of the audio file (since it is clear when it goes perfectly silent) and then end align rather than start ...


1

After a few hours of searching, I was only able to find this. I don't know if that's kind of what you are looking for, or at least gives you the info you need to modify the channel volume. I hope it helps!


1

RAM is not the critical part of a transcode, CPU is. Since it is working stream to stream, fairly minimal memory actually has to be required if the encoder is operating efficiently. The memory speed does matter for scratch space for the processor, but not so much the quantity. The CPU (or GPU if using GPU optimized encoding) is what does all the work and ...


1

You can use ffprobe (which comes with ffmpeg) to give you info about your movie files from the command line. You may require some shell-fu to convert the output of ffprobe into something you can use though. I've done this in the past; basically I pipe the output of ffprobe to sed or awk to grab the bits of info I need, then use this to drive the parameters ...


1

This is a "very" old question, but there is a pretty simple method to do this (and something that comes up surprisingly often). So if you landed here, I do hope you find this solution helpful. Change the individual slides to pdf. Turn the pdf to jpg Turn the jpg's into a film. To do this I have used unoconv, ghostscript, graphicsmagick and ffmpeg. ...


1

It works for me, but everything has a green tint and the higher the brightness the less any color but green is visible. Using a sony trinitron.


1

For that kind of quantity, you probably want to look in to a robotic solution that can load and transfer tapes unattended in to a cataloged system. Doing a quick search showed SAMMA as one promising option. I don't have any direct experience with this particular kind of problem, but I can't imagine that manual tape loading or buying an entire robotic ...


1

Your paper is asking for an impossible data point unless you have some method of evaluation specified. By definition, lossy compression results in a loss of data. Modern lossy compression is very good at discarding data that is not visually meaningful to people, but it is still discarding data. The amount of data loss when related to a human viewer is ...


1

There isn't a perfect answer to this problem. AVI and MP4 are just container's for video streams, so without knowing more about the actual streams in the containers, it is impossible to tell how much quality loss there would be, but as a general rule of thumb, it isn't all that atypical for AVI to use far less efficient video compression algorithms than MP4 ...


1

Because 4096 / 1920 = 2.13333 and 2160/1080 = 2. They are different aspect ratios, so yes, they end up letter boxing when you convert between them. That is the expected result. The 4K format you are using is a multiple of 2K and is not the same widescreen aspect ratio as 1080p. You can't translate between them without letterboxing, though there are ...


1

You are using the same bitrate for each video. The bitrate determines how much data is used per second. The resolution has nothing to do with how much data is used, it only impacts the number of points of data which are encoded (and thus determines part of the quality of the video output for a given bitrate). What you end up with is a lower resolution ...


1

MP4 files should be all you need. There shouldn't be any encryption on the files. It is possible you may need to download a codec. MP4 files are just a container format, so different codecs could be used within it. It is possible that you don't have the needed codec installed, but if you do, the files should just open in After Effects without issue.



Only top voted, non community-wiki answers of a minimum length are eligible