I have a WebM file with one video stream that was encoded with VP9 (libvpx-vp9). I wrote a C++ program to extract the frames from the video stream and save them out as PNG's. This works fine except that the resulting PNG's are missing alpha. If I extract the frames from the same WebM file using FFMPEG the resulting PNG's do contain alpha.I want to use vp9 encoder to encode video with alpha channel (argb -> webm, through ffmpeg) in real time (less than 30ms/frame), but I found that even if the -deadline realtime -speed 8 parameter is added, the speed is improved Still not obvious.Apr 22, 2020 · As you can see clock rate in input stream is 1/90000 (tbn 90k) , but in output 1/1000 (tbn 1k). How can I set a clock rate to 90k in output stream? Thanks a lot for help. EDIT I accept answer, because it is fact. But I solved my problem replacing webm container in -f parameter with rtp - and clock rate is 90k (tbn) 1 Answer. FFmpeg tries to detect the output container format based on the output filename but since NUL is not an actual filename, the format has to be specified. You may use the null muxer. ffmpeg -y -i input.mp4 -vcodec libvpx-vp9 -crf 31 -minrate 1500k -maxrate 4350k -pix_fmt yuv420p10le -colorspace 9 -slices 4 -color_range 2 -tile-columns 2 ...I am using a C code to detect pixel format of VP9 video stream in a WebM container. FFmpeg version 6.0, full shared library build, downloaded from official website. Operating system is Windows 10. I feed the library with a VP9 video encoded with alpha channel, pixel format is YUVA420p. It detects pixel format as YUV420p.Additionally to the previously mentioned arguments, ffmpeg VP9 and H265 codecs accept -crf flag . It enables constant quality mode, which guarantees a certain perceptual quality level within the entire video by passing a number from 0-63(VP9) and 0-51(H265), where 0 is the best quality and the maximum number is the worst.Jun 30, 2017 · I want to re-encode a stream from an IP camera to WebM (VP8 or VP9) format with ffmpeg. I need real time speed, but my CPU is a Core i5 (2017) and too busy (load avarage too more 100%). Can I buy hardware that is better suited for such an encoding task? What parametres for ffmpeg are recommended for transcoding in realtime? I find vp9 at a nominal 400k bit rate works great on 1280x720 video. (ffmpeg with libvpx-vp9 overshoots, and I typically end up with a 20% higher actual bit rate, 480k) 4K is 3840x2160, 9x the size of 1280x720, so it would seem a 3600k bit rate should produce good results. Another guide is that vp9 is reportedly about equal in quality to mp4 at ...Setting auto-alt-ref and lag-in-frames >= 12 -> Will turn on VP9's alt-ref frames. Speed - Useful to speed up the first pass. speed 4 - Ensures VP9 to encode really really fast, sacrificing the quality. c:a libopus -b:a 64k - Ensures ffmpeg to encode the audio in opus with a target of 64 Kilobits. speed 1 is a good speed vs. quality compromise.Jun 5, 2017 · ffmpeg -i input.mp4 -c:v vp9 -c:a libvorbis output.mkv. This will make a Matroska container with a VP9 video stream and a Vorbis audio stream, essentially the same as the WebM we made earlier. The command ffmpeg -codecs will print every codec FFmpeg knows about. The output of this command will change depending on the version of FFmpeg you have ... VP9 decoder consists of libvpx and ffvp9 (developed). Generally, it will adopt libvpx for VP9 decoding as default. If you have FFmpeg installed on Windows 10, you can utilize ffvp9 for VP9 decoding, which ffvp9 trounces libvpx by 25-50% in decoding speed on a bounty of machines. Moreover, WinX Video Converter is an optimum selection.FFmpeg's VP9 decoder takes advantage of a corpus of SIMD optimizations shared with other codecs to make it fast. A comparison made by an FFmpeg developer indicated that this was faster than libvpx, and compared to FFmpeg's h.264 decoder, "identical" performance for same-bitrate video, or about 10% faster for same-quality video. Patent claimsSetting auto-alt-ref and lag-in-frames >= 12 -> Will turn on VP9's alt-ref frames. Speed - Useful to speed up the first pass. speed 4 - Ensures VP9 to encode really really fast, sacrificing the quality. c:a libopus -b:a 64k - Ensures ffmpeg to encode the audio in opus with a target of 64 Kilobits. speed 1 is a good speed vs. quality compromise.ffmpeg -i input.mp4 -c:v libvpx-vp9 -minrate 5M -maxrate 5M -b:v 5M output.webm. Look at the output and increase or decrease the bit rate to your liking (or file size constraints). For example, you can use 500K or 5M, et cetera. You have to specify -minrate, -maxrate and the bitrate -b:v in order for the encoder to use CBR.May 28, 2018 · 1. What the VPx codecs in ffmpeg do is use the video bitrate value as a ceiling. If not set by the user, ffmpeg assumes a default of 200 kbps. You need to reset the value to get unconstrained CRF encoding. ffmpeg -y -i in.mkv -threads 6 -c:a libopus -c:v libvpx-vp9 -crf 30 -b:v 0 out.mkv. ddagrab (Desktop Duplication) video capture filter. ffmpeg -shortest_buf_duration option. ffmpeg now requires threading to be built. ffmpeg now runs every muxer in a separate thread. Add new mode to cropdetect filter to detect crop-area based on motion vectors and edges.对于基于 VP9 的基于 H/W 的编码，我仍然强烈建议使用vp9_vaapi编码器包装器，并带有警告（与使用 B 帧和速率控制模式有关）。VAAPI 总体上比 QSV 更稳定。 参考： 查看编码器选项，包括支持的速率控制方法： ffmpeg -h encoder=vp9_qsv 关于vpp_qsv过滤器的使用，请参见：I am using a C code to detect pixel format of VP9 video stream in a WebM container. FFmpeg version 6.0, full shared library build, downloaded from official website. Operating system is Windows 10. I feed the library with a VP9 video encoded with alpha channel, pixel format is YUVA420p. It detects pixel format as YUV420p.Live encoding with VP9 using FFmpeg Encoding parameters. VP9 provides a range of parameters to optimize live encoding. Some broad principles of these are discussed in Bitrate Modes. FFmpeg VP9 encoding example. The table below describes the parameters of an example ffmpeg call for VP9 encoding.ffmpeg -hwaccel qsv -c:v h264_qsv -i input.mp4 -f null - HEVC 10bit video decode and download as p010le yuv file ffmpeg -hwaccel qsv -c:v hevc_qsv -load_plugin hevc_hw -i input.mp4 -vf hwdownload,format=p010 -pix_fmt p010le output.yuv Encode-only. Check supported qsv encoder list ffmpeg -encoders|grep qsv Check private option list of h264 encoderI want to use vp9 encoder to encode video with alpha channel (argb -> webm, through ffmpeg) in real time (less than 30ms/frame), but I found that even if the -deadline realtime -speed 8 parameter is added, the speed is improved Still not obvious.Jun 30, 2017 · I want to re-encode a stream from an IP camera to WebM (VP8 or VP9) format with ffmpeg. I need real time speed, but my CPU is a Core i5 (2017) and too busy (load avarage too more 100%). Can I buy hardware that is better suited for such an encoding task? What parametres for ffmpeg are recommended for transcoding in realtime? ffmpeg -i input.mp4 -c:v vp9 -c:a libvorbis output.mkv. This will make a Matroska container with a VP9 video stream and a Vorbis audio stream, essentially the same as the WebM we made earlier. The command ffmpeg -codecs will print every codec FFmpeg knows about. The output of this command will change depending on the version of FFmpeg you have ...FFmpeg, as of time of writing, does not support resolution-changes mid-stream while encoding. There is a patchset to introduce this ability. motivated for raw video and VP8/9 encoders, but it stands abandoned. Vlc Media Player from videolan.org can convert vp9 to h264. Under the Media menu, choose Convert/Save.May 25, 2023 · FFmpeg command-line settings to enable VP9 Profile 2 and HDR EOTFs. Your FFmpeg will need to have been built with 10-bit (or even 12-bit) support. In the examples below we use a statically-built ffmpeg with 10-bit support. You may use our build script to make your own, or follow the guidance on the FFmpeg site. ffmpeg.exe -i webm_file_name.webm -pix_fmt yuv422p10le -c:v prores -profile:v 3 -vendor ap10 prores_file_name.mov Stick to H264. Seriously, H264 is supported by just about everything. At 1080P, the benefits of VP9 aren't tangible enough to be worth the incompatability headache.Aug 26, 2021 · I want to use vp9 encoder to encode video with alpha channel (argb -> webm, through ffmpeg) in real time (less than 30ms/frame), but I found that even if the -deadline realtime -speed 8 parameter is added, the speed is improved Still not obvious. Aug 15, 2015 · FFmpeg doesn't have a stable built-in AAC encoder, so this command will just copy the audio stream in the same format to the output file. If VLC still doesn't like the audio codec, you can change the copy in -c:a copy to some other codec listed here. ffmpeg -i <input file> -c:a copy -c:v libx264 <output file>. FFmpeg should automatically detect ... What you need is sws_scale functionality of ffmpeg. This does two things, scaling and format conversion, both can be performed same time. Check scaling_video.c example. I have a downscaled frame already for both h264 and vp9 to encode and would like to get the advantage of VP9's which having a smaller size but maintain similar quality as h264.As you can see clock rate in input stream is 1/90000 (tbn 90k) , but in output 1/1000 (tbn 1k). How can I set a clock rate to 90k in output stream? Thanks a lot for help. EDIT I accept answer, because it is fact. But I solved my problem replacing webm container in -f parameter with rtp - and clock rate is 90k (tbn)Dec 22, 2020 · FFmpeg (with librav1e, libaom-av1 and libsvtav1 included) runs fine on my Windows 8.1 machine and I'm able to convert the videos to H.264, H.265 and VP9 (all lossless) using the Commands section from AV1 vs VP9 vs AVC (h.264) vs HEVC (h.265): Part I - Lossless. But I'm confused with the command line parameters for AV1 on that page. ffmpeg -i input.mp4 -c:v libvpx-vp9 -minrate 5M -maxrate 5M -b:v 5M output.webm. Look at the output and increase or decrease the bit rate to your liking (or file size constraints). For example, you can use 500K or 5M, et cetera. You have to specify -minrate, -maxrate and the bitrate -b:v in order for the encoder to use CBR.Jun 28, 2017 · When I try to encode a video file with a two pass in ffmpeg, the output file of the first pass is empty using vp9. Hence I can not proceed with the second part. Code for the two-pass: 1.pass: ffmpeg -y -s:v 3840x1920 -framerate 30 -i video_framerate_resolution.yuv -c:v libvpx-vp9 -crf 20 -pass 1 -an -f avi NULL && \ 2.pass FFmpeg command-line settings to enable VP9 Profile 2 and HDR EOTFs. Your FFmpeg will need to have been built with 10-bit (or even 12-bit) support. In the examples below we use a statically-built ffmpeg with 10-bit support. You may use our build script to make your own, or follow the guidance on the FFmpeg site.Nov 20, 2018 · What you need is sws_scale functionality of ffmpeg. This does two things, scaling and format conversion, both can be performed same time. Check scaling_video.c example. I have a downscaled frame already for both h264 and vp9 to encode and would like to get the advantage of VP9's which having a smaller size but maintain similar quality as h264. FFMPEG with VP9 + RTSP. Ask Question Asked 2 years, 11 months ago. Modified 2 years, 8 months ago. Viewed 2k times 4 When we use HEVC + RTSP, ffmpeg works fine. ...I have a WebM file with one video stream that was encoded with VP9 (libvpx-vp9). I wrote a C++ program to extract the frames from the video stream and save them out as PNG's. This works fine except that the resulting PNG's are missing alpha. If I extract the frames from the same WebM file using FFMPEG the resulting PNG's do contain alpha.FFmpeg supports following functionality accelerated by video hardware on NVIDIA GPUs: Hardware-accelerated decoding of H.264, HEVC, VP9, VP8, MPEG2, MPEG4*, and AV1. Granular control over encoding settings such as encoding preset, rate control and other video quality parameters. Create high-performance end-to-end hardware-accelerated video ... FFmpeg command-line settings to enable VP9 Profile 2 and HDR EOTFs. Your FFmpeg will need to have been built with 10-bit (or even 12-bit) support. In the examples below we use a statically-built ffmpeg with 10-bit support. You may use our build script to make your own, or follow the guidance on the FFmpeg site.I find vp9 at a nominal 400k bit rate works great on 1280x720 video. (ffmpeg with libvpx-vp9 overshoots, and I typically end up with a 20% higher actual bit rate, 480k) 4K is 3840x2160, 9x the size of 1280x720, so it would seem a 3600k bit rate should produce good results. Another guide is that vp9 is reportedly about equal in quality to mp4 at ...If it cannot, ffmpeg will abort and all output files will fail to be processed. The solution is to specify WebM-compatible codecs for both audio and video. For video (-c:v), WebM only supports VP8 and VP9 - and technically AV1 as well: For VP8, use -c:v libvpx -crf 15 -b:v 1M; For VP9, use -c:v libvpx-vp9 -crf 30 -b:v 0ffmpeg v4.0.2 or higher can encode/transcode VP9 in mp4. Commandline (when transcoding): ffmpeg -i INPUT.MKV -c:v libvpx-vp9 OUTPUT.MP4. Commandline (when remuxing (Super fast)): ffmpeg -i INPUT.MKV -c:v copy OUTPUT.MP4. Your second command isn't transcoding, it's called remuxing, the process of moving encoded streams from one container to ... Aug 5, 2011 · On Windows 7 I had to use the power shell (Start > Accessories > Windows Power Shell > Power Shell) and provide the full location for ffmpeg, input and output. Note the parameter -vcodec libvpx uses VP8 by default. To use VP9 replace with -vcodec libvpx-vp9. WedmbSD For boost encode without decreasing quality -row-mt 1. Threaded tile -tile-columns 0 but can be for little threaded boost: 1 for 720p, 2 for 1080p, 3 for 2160p, 0 for non-HD or better quality. Don't set it > Set OFF other -tile-rows 0 and -frame-parallel 0, don't boost and can decrease quality.Slow VP8 and VP9 encoding with ffmpeg. 1. Incorrect FPS when muxing VP9-encoded data into .webm. 0. ffmpeg encoding with VP8 producing bad looking video. 0.Sep 19, 2020 · Use both -deadline and -cpu-used to control speed. -deadline has 3 modes: best, good, and rt. The -cpu-used option can tweak each mode to further adjust speed. The meaning/value of -cpu-used depends on the mode. best - This usually gives the best quality output but is extremely slow. You should use VP9, it's slower, but the quality gain is worth it. There is not a lot of gain to tweak each options, you'll have really good results with ffmpeg -i in.mp4 -c:v libvpx-vp9 -crf 30 -b:v 0 -c:a libopus -b:a 64k -vbr on out.webm-crf is the quality level, the lower the better Jun 17, 2013 · ffmpeg is the best tool for encoding/transcoding video to VP9. The amount of options you need to software encode VP9 efficiently on a modern CPU is, sadly, staggering. Creating a simple script with all the options required and/or desired is therefore likely preferable to remembering all of them. This setup with that command encodes at ~126 fps. This compares to about 10 fps using libvpx-vp9 encoder! Using the global_quality of 70 for hardware encoding the file is about 60% bigger than an encoding using libvpx-vp9 at a crf of 32. I would say these settings give about the same quality degradation compared to the source.Formula code: ffmpeg.rb on GitHub. Bottle (binary package) installation support provided for: ... VP8/VP9 video codec: opencore-amr: 0.1.6: Audio codecs extracted ...May 25, 2023 · A variety of encoding products and cloud service providers allow you to encode VP9 video. These pages assume you are using FFmpeg . You can download a pre-compiled version of FFmpeg, or compile FFmpeg with the --enable-libvpx option on your system. 3 Answers Sorted by: 6 Basically ffmpeg supports VP9 encoding and decoding. It looks like your build of libvpx doesn't support VP9. For VP9 support you must use the experimental branch: $ git clone -b experimental http://git.chromium.org/webm/libvpx.git $ cd libvpx $ ./configure --enable-vp9 --enable-shared $ make && make install But with ffmpeg qmax may have different meaning as it's a codec dependent parameters. for x264 it should be a quantizer see here, But with some others codecs it doesn't represent a quantization level but a quality range. qmax and qmin are the 'quality-ranges' in which you define to encode. Oposite from what most, atleast me, would expect is ...This setup with that command encodes at ~126 fps. This compares to about 10 fps using libvpx-vp9 encoder! Using the global_quality of 70 for hardware encoding the file is about 60% bigger than an encoding using libvpx-vp9 at a crf of 32. I would say these settings give about the same quality degradation compared to the source. But with ffmpeg qmax may have different meaning as it's a codec dependent parameters. for x264 it should be a quantizer see here, But with some others codecs it doesn't represent a quantization level but a quality range. qmax and qmin are the 'quality-ranges' in which you define to encode. Oposite from what most, atleast me, would expect is ...Formula code: ffmpeg.rb on GitHub. Bottle (binary package) installation support provided for: ... VP8/VP9 video codec: opencore-amr: 0.1.6: Audio codecs extracted ...Nov 20, 2018 · What you need is sws_scale functionality of ffmpeg. This does two things, scaling and format conversion, both can be performed same time. Check scaling_video.c example. I have a downscaled frame already for both h264 and vp9 to encode and would like to get the advantage of VP9's which having a smaller size but maintain similar quality as h264. May 25, 2023 · FFmpeg command-line settings to enable VP9 Profile 2 and HDR EOTFs. Your FFmpeg will need to have been built with 10-bit (or even 12-bit) support. In the examples below we use a statically-built ffmpeg with 10-bit support. You may use our build script to make your own, or follow the guidance on the FFmpeg site. If it cannot, ffmpeg will abort and all output files will fail to be processed. The solution is to specify WebM-compatible codecs for both audio and video. For video (-c:v), WebM only supports VP8 and VP9 - and technically AV1 as well: For VP8, use -c:v libvpx -crf 15 -b:v 1M; For VP9, use -c:v libvpx-vp9 -crf 30 -b:v 0Mar 3, 2023 · Steps to reproduce: First, with a 4K 120fps video clip with a green screen, create a HEVC .mov file: ffmpeg -i input.mp4 -vf colorkey=0x00b140:0.3:0.1 -vcodec hevc_videotoolbox -alpha_quality 0.1 -tag:v hvc1 out.mov Then, run the following command: ffmpeg -i out.mov -c:v libvpx-vp9 out.webm. This resulting Webm won't play at all. Jun 17, 2013 · ffmpeg is the best tool for encoding/transcoding video to VP9. The amount of options you need to software encode VP9 efficiently on a modern CPU is, sadly, staggering. Creating a simple script with all the options required and/or desired is therefore likely preferable to remembering all of them. I can encode the video to vp9 into webm container with the following command which correctly produces a vp9 video with transparency: ffmpeg -c:v libvpx -i dancer1.webm -c:v libvpx-vp9 dancer_vp9.webm. So basically forcing libvpx encoders instead of ffmpeg native ones to support alpha. However if I try to use ivf container instead of webm the ...If you are on windows, the recommended way to get these tools and build FFmpeg is through msys2. The way to get these specific tools will not be provided here though. The way to get these specific tools will not be provided here though. ffmpeg -i output.mp4 -vcodec libvpx-vp9 -strict experimental output_2.webm ffmpeg -i output_2.webm -strict 2 output_3.mp4 This happens only with some youtube videos, not all of them. Is there a way to download all youtube videos in a readable format with only one command line, without having to convert to webm?Note: FFmpeg must be compiled with the --enable-libvpx option for VP9 to work. Most pre-compiled versions include this option by default. If your version of FFmpeg does not create VP9, it may be missing this compilation option. FFmpeg is a command-line program. Once you have it installed, you can perform encodes from the command line.Dec 10, 2020 · 对于基于 VP9 的基于 H/W 的编码，我仍然强烈建议使用vp9_vaapi编码器包装器，并带有警告（与使用 B 帧和速率控制模式有关）。VAAPI 总体上比 QSV 更稳定。 参考： 查看编码器选项，包括支持的速率控制方法： ffmpeg -h encoder=vp9_qsv 关于vpp_qsv过滤器的使用，请参见： Since 2016-07-13, it's possible to encode VP9/webm videos with alpha channel (VP9a). You only need a copy of ffmpeg compiled after that date. By the way, all you need to write is: ffmpeg -i frames/%03d.png output.webm FFmpeg understands png format and will set a default framerate of 25 fps and a yuva420p pixel format to the output. 5. I believe I found a solution: ffmpeg -hwaccel auto -i in.mp4 -c:v h264_nvenc -preset llhq -rc constqp -qp 21 -c:a copy out.mp4. It seems that h264_nvenc uses -qp instead of -crf. This option only works while -rc is set to constqp. Share. Improve this answer. Follow. answered Jan 26, 2018 at 18:50.Nov 14, 2013 · But with ffmpeg qmax may have different meaning as it's a codec dependent parameters. for x264 it should be a quantizer see here, But with some others codecs it doesn't represent a quantization level but a quality range. qmax and qmin are the 'quality-ranges' in which you define to encode. Oposite from what most, atleast me, would expect is ... After quite a lot of tests, I ended up with the -crf 23 setting, with which the result webm file is of very good quality, compared to the original. The exact ffmpeg commands are: First pass: ffmpeg -i Source.mov -c:v libvpx-vp9 -pass 1 -pix_fmt yuv420p -b:v 0 -crf 15 -threads 2 -speed 4 -tile-columns 6 -frame-parallel 1 -an -y -f webm /dev/null.Jul 12, 2023 · ffmpeg -y -hwaccel_output_format d3d11 -hwaccel d3d11va -i input.mp4 -c:v hevc_nvenc out.mp4 NVDEC/CUVID. NVDEC offers decoders for H.264, HEVC, MJPEG, MPEG-1/2/4, VP8/VP9, VC-1, AV1. Codec support varies by hardware (see the GPU compatibility table). Note that FFmpeg offers both NVDEC and CUVID hwaccels. They differ in how frames are decoded ... 5. I believe I found a solution: ffmpeg -hwaccel auto -i in.mp4 -c:v h264_nvenc -preset llhq -rc constqp -qp 21 -c:a copy out.mp4. It seems that h264_nvenc uses -qp instead of -crf. This option only works while -rc is set to constqp. Share. Improve this answer. Follow. answered Jan 26, 2018 at 18:50.If you're encoding vp9 (webm), try ( docs ): ffmpeg -i file -c:v libvpx-vp9 -g 25 [speed/rate control options] out.webm. Both commands will place a new keyframe every 25 frames. If you want more than that (e.g. one keyframe every frame), then perhaps you don't care about compression as much as you care about speed, and it may be worth looking ...3 Answers Sorted by: 6 Basically ffmpeg supports VP9 encoding and decoding. It looks like your build of libvpx doesn't support VP9. For VP9 support you must use the experimental branch: $ git clone -b experimental http://git.chromium.org/webm/libvpx.git $ cd libvpx $ ./configure --enable-vp9 --enable-shared $ make && make install Feb 4, 2015 · ffmpeg -i video.webm -i audio.opus -c:v copy -c:a aac -strict experimental output.mp4. it should look something like this. ffmpeg -i audio.opus -i vid.webm -c:v copy -c:a opus -strict experimental output6.webm. replace aac with opus and the two files around with opus being in front (i think), it should work. Share. If you are on windows, the recommended way to get these tools and build FFmpeg is through msys2. The way to get these specific tools will not be provided here though. The way to get these specific tools will not be provided here though. ffmpeg -hwaccel qsv -c:v h264_qsv -i input.mp4 -f null - HEVC 10bit video decode and download as p010le yuv file ffmpeg -hwaccel qsv -c:v hevc_qsv -load_plugin hevc_hw -i input.mp4 -vf hwdownload,format=p010 -pix_fmt p010le output.yuv Encode-only. Check supported qsv encoder list ffmpeg -encoders|grep qsv Check private option list of h264 encoderI want to use vp9 encoder to encode video with alpha channel (argb -> webm, through ffmpeg) in real time (less than 30ms/frame), but I found that even if the -deadline realtime -speed 8 parameter is added, the speed is improved Still not obvious.Dec 24, 2017 · Slow VP8 and VP9 encoding with ffmpeg. 1. Incorrect FPS when muxing VP9-encoded data into .webm. 0. ffmpeg encoding with VP8 producing bad looking video. 0. ffmpeg -i output.mp4 -vcodec libvpx-vp9 -strict experimental output_2.webm ffmpeg -i output_2.webm -strict 2 output_3.mp4 This happens only with some youtube videos, not all of them. Is there a way to download all youtube videos in a readable format with only one command line, without having to convert to webm?对于基于 VP9 的基于 H/W 的编码，我仍然强烈建议使用vp9_vaapi编码器包装器，并带有警告（与使用 B 帧和速率控制模式有关）。VAAPI 总体上比 QSV 更稳定。 参考： 查看编码器选项，包括支持的速率控制方法： ffmpeg -h encoder=vp9_qsv 关于vpp_qsv过滤器的使用，请参见：It seems that the ffmpeg -quality command is the same as the -deadline command. These commands do not directly affect the other options, but merely determine the amount of time the encoder is allowed to spend on any particular frame. As commented in the vpx_encoder.h file in the libvpx code: The encoder supports the notion of a soft real-time ...So far we’ve identified a few codecs and technologies we can use to keep track of transparency in videos. Lets take a look at how the ffmpeg tool is used practically to create animated video content with an alpha channel. Then we will dive into animating and masking existing videos with ffmpeg. Using FFMPEG to Encode VP9 with Alpha Channel
There’s basically two ways to measure this: same-bitrate (e.g. a 500kbps VP8 file vs. a 500kbps VP9 file, where the VP9 file likely looks much better), or same-quality (e.g. a VP8 file with SSIM=19.2 vs. a VP9 file with SSIM=19.2, where the VP9 file likely has a much lower bitrate). We did same-quality measurements, and found:. Freeslots.com mountain fox
Mar 19, 2021 · I have a WebM file with one video stream that was encoded with VP9 (libvpx-vp9). I wrote a C++ program to extract the frames from the video stream and save them out as PNG's. This works fine except that the resulting PNG's are missing alpha. If I extract the frames from the same WebM file using FFMPEG the resulting PNG's do contain alpha. ffmpeg -i input.mp4 -c:v libvpx-vp9 -b:a 128k -b:v 1M -c:a libopus output.webm The results aren't great, video has lost lot's of it's sharpness. Looking at the original file I can see the bitrate is 1694kb/s. Are there any settings I can add or change to improve the output? Would maybe a 2 pass encode improve things?Aug 1, 2017 · 5. I believe I found a solution: ffmpeg -hwaccel auto -i in.mp4 -c:v h264_nvenc -preset llhq -rc constqp -qp 21 -c:a copy out.mp4. It seems that h264_nvenc uses -qp instead of -crf. This option only works while -rc is set to constqp. Share. Improve this answer. Follow. answered Jan 26, 2018 at 18:50. Oct 13, 2019 · 1 Answer. FFmpeg tries to detect the output container format based on the output filename but since NUL is not an actual filename, the format has to be specified. You may use the null muxer. ffmpeg -y -i input.mp4 -vcodec libvpx-vp9 -crf 31 -minrate 1500k -maxrate 4350k -pix_fmt yuv420p10le -colorspace 9 -slices 4 -color_range 2 -tile-columns 2 ... Sep 23, 2014 · As of today, FFmpeg and libav have implemented hardware-accelerated encoding via VAAPI on supported platforms and hardware SKUs, and I have written a write-up on the same that will enable you to set up, deploy and use both ffmpeg and libav to achieve the same effect. If you are on windows, the recommended way to get these tools and build FFmpeg is through msys2. The way to get these specific tools will not be provided here though. The way to get these specific tools will not be provided here though. There are two methods within ffmpeg that can be used to concatenate files of the same type: the concat ''demuxer''. the concat ''protocol''. The demuxer is more flexible – it requires the same codecs, but different container formats can be used; and it can be used with any container formats, while the protocol only works with a select few ...ffmpeg -y -hwaccel_output_format d3d11 -hwaccel d3d11va -i input.mp4 -c:v hevc_nvenc out.mp4 NVDEC/CUVID. NVDEC offers decoders for H.264, HEVC, MJPEG, MPEG-1/2/4, VP8/VP9, VC-1, AV1. Codec support varies by hardware (see the GPU compatibility table). Note that FFmpeg offers both NVDEC and CUVID hwaccels. They differ in how frames are decoded ...Even some "lossless" variants of codecs (e.g. libvpx-vp9 -lossless) produce distorted colors due to the YUV colorspace. If non-exact colors are acceptable, then the libvpx codec can make quite a good job: ffmpeg -r 25 -i image%03d.png -c:v libvpx -crf 4 -b:v 0 output.webmFeb 22, 2014 · This seems to be similar to what people report about HEVC (using e.g. x265 as an encoder). single-threaded decoding speed of libvpx isn’t great. FFvp9 beats it by 25-50% on a variety of machines. FFvp9 is somewhat slower than ffvp8, and somewhat faster than ffh264 decoding speed (for files encoded to matching SSIM scores). FFmpeg, as of time of writing, does not support resolution-changes mid-stream while encoding. There is a patchset to introduce this ability. motivated for raw video and VP8/9 encoders, but it stands abandoned. Vlc Media Player from videolan.org can convert vp9 to h264. Under the Media menu, choose Convert/Save.FFMPEG with VP9 + RTSP. Ask Question Asked 2 years, 11 months ago. Modified 2 years, 8 months ago. Viewed 2k times 4 When we use HEVC + RTSP, ffmpeg works fine. ....