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5

"Q: Is it better to have more B-frames or more P-frame for video streaming?". From: https://en.wikipedia.org/wiki/Video_compression_picture_types The three major picture types used in the different video algorithms are I, P and B. They are different in the following characteristics: I‑frames are the least compressible but don't require other ...


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Per the OP's request, I will attempt to explicitly answer his single-sentence questions. First I need you to define bit rate. Bit rate is the number of bits per second used to encode a video stream (which itself has an implicit data rate based on the number of pixels (width x height), the pixel depth (dynamic range, color gamut), and frame rate). Here is ...


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Why is the duration changed? MP3s may not display accurate duration, depending on whether a Xing header was written, and whether the MP3 encoding is Variable Bit Rate (VBR) or a Constant Bit Rate (CBR). What is the difference between the first bitrate (from Duration: ) and the second one (from Stream: )? The first one is the division of the total file size (...


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No, because it's content dependent. Video with high motion contains more information than a nearly still scene does. Hence it takes more bits to encode.


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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 ...


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It does not make sense to speak of the size of an encoded frame in an inter-coded video stream, which is typical of MPEG-X videos. I-frames are self-contained but P- and B- frames are predicted frames and the final decoded result uses data from various inputs. On the other hand, the size of a single Group of Pictures (GOP) may be a meaningful measure. The ...


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That max_bit_rate is a a tag written by some encoders, when set by the user in the export dialog box. It is not an indication of the maximum bitrate found if you were to survey the encoded bitstream. It's possible to get a good idea of the maximum bitrate of a stream this way: ffmpeg -i in.mp4 -map 0:v -c copy -f segment -segment_time 1 -...


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This depends on the specific encoder, and the compression standard, by itself, may not have anything to say about it. x264, which encodes to H.264, takes frame duration, into account, in its ratecontrol algorithm. From the source code (my emphasis): Ratecontrol lowers relative quality at higher framerates and the reverse at lower framerates; this ...


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Step 4 (first attempt) will work if you re-encode the 2nd video like the first (without the filters). What's happening is that besides the timescale difference between CC's output and ffmpeg's (which will only result in timing errors), x264 is producing a High profile stream with a different parameter set than CC's encoder. Re-encode the 2nd video with ...


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In theory, if the number of keyframes and their placement were about the same, as decided by the encoder, then yes, you can reduce the bitrate to half and retain the same quality. In practice, the encoder may be configured to place a keyframe every N seconds, in which case, you should use a bitrate a bit higher than half the original bitrate, say, around 55%....


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Could you give files (or png screenshots) to comparing? I think that file with higher bitrate and higher resolution should look better, with other conditions being equal. 1056*594 = 627 264 pixels. 1280*720 = 921 600 pixels (47% more pixels relative to 1056x594 resolution) 921 600 / 627 264 = 1.469 * 100% = 147% relative to 1056x594 resolution. 2966 kbps ...


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Your program probably re-encoded the resulting video file from scratch and used whatever setting it considered okay. If you want to have more control about the process and/or do not want it to re-encode the video at all (if both are of the same format), then I strongly suggest looking into ffmpeg for this. For reference, https://trac.ffmpeg.org/wiki/...


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Adaptive streaming is accomplished by switching between pre-encoded streams of different bitrates and/or resolutions. But the bitrate within any given pre-encoded stream does not vary too much. YT-DL, with your command, will select the 'best' video stream, usually the one with the highest bitrate and resolution, and return its URL. This URL is a direct ...


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That would be a great question for Canon, because only the manufacturer can provide the reasons considered when producing a new model. I only can venture a guess that the M6 is a smaller camera that presumably is a lower-level compared to full-body T5. Maybe higher bitrate results in more heat, and the smaller body may have issues with dissipating it. Your ...


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Yes. But you should have a little overhead as well, so you probably need about 150Mbps for this. Something like huffyuv could give about a 50% reduction, or a lossy codec would give 95% or more reduction.


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You get banding because of colormatrix filter. Better use colorspace filter, and use it if really needed, when source is really not in rec709.


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Like much with technology (and life), it depends. You didn't specify what software, protocol, or codec you are streaming with, so there are quite a few variables. Will the bit rate drop? If you are using a constant bit rate (CBR) codec, no it will not. As the name implies, the bit rate is always the same regardless of the content. If you are using a ...


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so all that is captured in the live video stream is a red light bulb and a black background No. You can't get black background. You will get any possible type of noises, many shadows and all kinds artifacts of camera's matrix. will the new bitrate be less than X? No. As GoPro writes constant bitrate (CBR) No. As new noises can require even more ...


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I missed the -re flag that would limit speed of reading the generators at a speed of playback. My ffmpeg was streaming data to Periscope as fast as it can, much faster than a live stream would, thus exceeding the bitrate limits. Working code, that will stream a test table with a timecode running on top of it to Periscope: ffmpeg \ -re \ -f lavfi \ ...


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You can use option -ab, like -ab 32000 for 32kbit/s bitrate audio. But here may be problem: not all codecs (encoders) can support so small bitrate. For example, libaacplus can do even smaller, but it was removed from ffmpeg. You can use options -qmix and -qmax for define video quality. Try something like -qmin 32 -qmax 64. Also, check -bufsize, you set it ...


1

Entropy Entropy is an important and notoriously difficult to teach (and understand) concept in physics. It's often explained as a measure of disorder, though that's not technically correct. However, from this perspective a video with lots of small particles would be considered to have a higher entropy than a video showing a black screen, for example. Read ...


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The ffprobe command below will spit out the bitrate: ffprobe in.mp4 -select_streams v -show_entries stream=bit_rate -of compact=p=0:nk=1 e.g. 4118620 If the result is greater than 4000000 then you can add -b:v 4000k -bufsize 4000k -maxrate:v 4000k. Or you can add it anyway. Set -c:v to copy if the stream is under 4000000 else to libx264. The three values ...


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Since Mulvya's habit of answering questions in the comments ruins our answer rate statistic, let's put this into an answer °v° Which is 4 Mbps. Now OBS is asking for video bitrate, how do I convert 4 Mbps to bitrate OBS is asking for? Bitrate is the general term for the amount of bits per second (1 bit = 1 unit of information). Mbps stands for Mega bit ...


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Yes this feature exists, but it is not widely used yet. Texas Instrument developped such solution, called SmartCodec, which looks to be implemented in a Samsung video surveillance system: Megapixel Camera This is a HW based solution, that is for market of video surveillance. I think it would be implemented in future video codecs HEVC, adopted by many ...


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Is there any technique (encoding/compression/etc.) that can improve the quality of the foreground elements when such a background is present in the shot? I don't know of any encoding algorithm that can differentiate between objects in a video and allocate different amounts of bits for those objects based on how important they are. That's not really how ...


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What could do is show that Youtube transcodes to 4K at bitrates of ~20 mbps. You can use a tool like youtube-dl to check. Run youtube-dl -F URL So, your upload and download times will increase by a factor of 13-14, compared to the 1.5 mbps stream for 576p that you currently use. Youtube is best placed in terms of expertise and motivation to minimize ...


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