Hot answers tagged

7

tl;dr: Since Youtube reencodes all videos regardless of the upload format, it really isn't that important. Just export your video with a high bitrate to preserve quality. Also see my answer here regarding quality loss caused by Youtube. Long answer: Each reencoding of a video to a compressed format lowers the quality. Usually, that means you'll lose quality ...


5

YouTube will re-encode whatever you give it. VP9 is currently too slow to encode. So the best choice is to either: Give it the original footage, or if it is not accepted by YouTube or is too big to upload, then... Re-encode to H.264 ffmpeg ffmpeg will accept just about any input and will provide a great quality output. Development is very active, so it ...


4

If the frame-rate is not too high and you can associate a frame with a precise timestamp then the easiest would be to add the metadata as textual subtitles. The other option is to mux the metadata as standard headers in .mp4 or similar container format. .mp4 can be broken down into multiple fragments, each one with its own header, and theoretically this can ...


4

Although @stib's advice is sound, I disagree with "to get an appreciable size reduction you would have to throw away a lot of quality". Cameras have to compress on-the-fly, so they use constrained baseline mode, which is to say, they skip most of the tricks that H.264 codec uses to efficiently compress videos. If space isn't a pressing concern, keep them ...


3

The fourth stream apparently is a CEA-608 subtitle stream, which during the days of analog television signal transmission was caption data embedded within the video data. Apparently FFmpeg can extract it but can't mux it to a new container. As for stripping only the audio, MP4Box may be of help.


3

You can only estimate the bitrate as proportion of your crop. If you have 30,000 Kbps for 1920*1080 pixel, then for 1080*1080 pixel this would mean 16,875 Kbps. If there is more complexity inside the crop region than outside, I would even increase the target bitrate further. However, if your videos are not that long and not intended for streaming I wouldn't ...


3

Judge based on the quality rather than the bitrate value. Use CRF mode encoding and if the quality isn't what you can accept, decrease the CRF value. ffmpeg -i "%%a" -s 3840x2610 -c:v libx264 -crf 18 -acodec copy D:\%%~na.mp4


3

Rotate without re-encoding You can add rotation metadata: ffmpeg -i input.3gp -c copy -metadata:s:v rotate=90 output.3gp -c copy will enable stream copy mode, so it will just re-mux instead of re-encode. Player and device support for the rotate metadata may vary, so your player or device may not actually rotate the video. If that is the case you may ...


3

Players buffer streams. The bigger the buffer size, the longer window the encoder has to use higher bitrates for hard content, and then fewer bits earlier or later on easy content, to achieve similar quality for the whole video. I'll assume you're going to use h.264 (aka AVC) as a codec, as it's the de-facto standard for streaming video on the Internet. ...


3

Yes, you have the right idea. If stib's suggestion of making multiple outputs in parallel with the same ffmpeg commandline doesn't quite do the trick, then use a temp file to hold a lossless copy of the output of any slow filtering: ffmpeg -i src.mkv -vf yadif=3:1,mcdeint=2:1 -c:a copy -c:v libx264 -preset ultrafast -qp 0 deinterlaced.mkv (never use ...


3

I would get as far away from EE as possible. Using the x264 tool, and mp4box, you can convert and segment out the files which are ready to be streamed to any dash compatible players. Especially since you mentioned using batch scripts, this is a great solution I think. This is a good guide: ...


2

I'm not sure how this fits into a streaming strategy, but the DPX file format includes per-frame metadata (potentially a great deal of it). This Wikipedia article has the basic info. I'm also not clear on what you mean by 'bound permanently'. In the AVI file container the "I" stands for "Interleaved", where video and audio packets (roughly) alternate in the ...


2

Any decent encoder can hit a target bitrate (with 2pass), but still spend the bits intelligently to achieve similar quality throughout the file. x264 2pass figures out what CRF will give the desired bitrate (pass1), and then uses it (pass2). (source: Dark Shikari. cf. the links I dug up for my answer on this question about VBR streaming). You only get ...


2

Maybe someone will chime in with an app suggestion that directly fulfills your need, but here's a temporary workaround - a bit convoluted, but should work. Create two folders A and B. Set folder A as the destination folder in the encoder. Apply a suffix to all the output files being generated, something innocuous like ENC e.g. Clip2015-09-25-23232-ENC.mov ...


2

Yes, MPEG-2 video is stored as YCbCr, but video editing programs (like Cinelerra) convert the samples to RGB for processing during editing. That range is 16-235. From Wikipedia on YCbCr Analog YPbPr from analog R'G'B' is derived as follows: To get a YUV output in the 16-235 range, the input RGB is also limited.


2

In strict mathematical terms, no. In terms of maintaining an acceptable image quality, yes. If you use CRF 18 and a preset like ultrafast now, you should be able to get a smaller acceptable file with preset veryslow later on.


2

Strictly speaking, fourcc is the codec ID used by Microsoft. It has been adapted for use with many other formats, thus making it seem like a standardized ID format, but it's not. ffmpeg, in particular, seems to only consider XDCAM standard MPEG2 for inclusion in MOV. From the source code: else if (track->enc->codec_id == AV_CODEC_ID_MPEG2VIDEO) ...


2

You can't avoid the re-encode. They do this to be sure that every video they serve is in a standardized format, resolution and bitrate. It would be inefficient and risky to vet all diverse set of incoming files to check if they meet all their parameters, some of which are not easily available to set or tweak at the user's end.


1

The Apple video uses a profile with fewer reference frames and also carries a streaming hint track. The following ffmpeg command template should create a quick seeking MP4 file: ffmpeg -i input -c:v libx264 -profile:v baseline -x264opts keyint=3:min-keyint=2 -{other video encoding parameters} -{audio encoding parameters} -movflags +faststart+rtphint ...


1

Yes, TS is capable of doing what you are asking. Weather OBS is, is another question (that I do not know the answer to). mkv MAY be also to as well. But mp4 and mov can not do this.


1

With Adobe you can render most things through Adobe Media Encoder. AME has the ability to render one project file as different formats and you can actually create somewhat of a list and it will treat it as a queue.


1

Unfortunately I couldn't find it in Adobe Encoder preferences - there is no such settings, and by default it loads 30fps sequence. You can change the default in Media Encoder by going to the Preferences/Media and then change "Indeterminate Media Timebase"


1

WMV is not lossless. As all distribution formats, it's highly compressed. An AVI file can of course be uncompressed, but on the Mac version of AE, AVI is only available as a Quicktime export component (ie, it appears in File > Export) which is really not a recommended path to export video files from After Effects. Same for Flip4Mac. So, yes, exporting a ...


1

Upscaling at playback time is done by graphics hardware, not the CPU, so your assumption turns out to be false. Good software players will feed the video through high-quality hardware scaling (e.g. mpv's opengl-hq video-out). HW upscaling might still default to bilinear, though, so it's worth thinking about this. Upscaling before encode spreads the detail ...


1

I have used both on my Ninja Blade with my C100, no real difference in quality across drastically different circumstances (night vs day). Pro Res works better on Mac, DNXHD works better on Windows. It all comes down to your OS, and whether you have to share the files with broadcasters (in which case I would use DNX as a lot of editors use Avid). Other then ...


1

AVCHD appears to just be h.264 with some constraints. Mainly on framerate and resolution. It looks from the wikipedia page that early versions mostly favoured interlaced encoding, unless you drop down to 720p. The wiki page doesn't say, but I assume it's H.264 4:2:0 8-bit, not Hi10 profile or something. I also have no idea what quality the hardware ...


1

You focus on quality in your question, so the answer is clear: ProRes (in various flavors) offers superior quality. There are other reasons you might choose AVCHD, but they don't relate to quality. AVCHD is generally speaking a distribution format, while ProRes is more an acquisition and intermediate format (it uses all I-frames). ProRes also comes in a ...


1

I think MeGUI is supposed to be a good front-end for x264 encoding. (x264 is the same h.264 encoder that VLC uses.) I don't know anything about powerdirector, so all I can say is that x264 is the best h.264 encoder (best quality vs. bitrate vs. cpu time tradeoff), and it's free. It's what you should use to make files for upload to youtube. (Use lots of ...


1

If you must encode at each step, use a lossless codec, or at least at a high bit rate and bit depth. But it's unusual and inefficient to perform intermediate encodings. A decent NLE will let you apply the needed transforms on separate segments or layers and only encode as a final step. And note that rendering doesn't imply encoding in the final format. It ...


1

If you are archiving the video you're not going to get better quality than the original files. So why not just save those and a copy of the project? To make it easier you can use the project manager File>Project Manager> to save just the media you use in your project (or you can transcode and trim the clips if you wish). Saving the original clips means you ...



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