On Sun, 1 Nov 2020 21:11:53 -0300 Diego Patricio Durante <[email protected]> wrote:
> Hello community! I have RTSP streams from cameras, and I'm interested > to save it to a disk and share as MP4. The main problems are the trade > off between disk usage and CPU usage without converting the format nor > scaling the image sizes. more exact words is "without changing", not "converting" ? > > I'm using Ubuntu 18.04 and saving chunk videos directly from RTSP > (h264), resizing the stream without using much more CPU. I'm using > ffmpeg and its dependencies installed directly from repositories. > > Actual test: > * I'm using it on Azure, with an Intel Xeon server (for testing > purposes I have instanced two cores: https://pastebin.com/VauHZtLx), > but the idea is to select a good trade off between performance and > cost to get about 70 streams. I have seen that libx264 outputs a > generic flags usage trough ffmpeg: > * * using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 > AVX2 But I have the same outputs and CPU times on my I7 4th > generation CPU. Using the time command, to get > * The input is (full ffprobe on https://pastebin.com/0dT9ttLG): > Stream #0:0: Video: mpeg4 (Simple Profile), yuv420p, 640x480 [SAR > 1:1 DAR 4:3], 30 tbr, 30k tbn, 1k tbc > Stream #0:1: Audio: amr_nb, 8000 Hz, mono, flt > * With this CPU I have tested to convert 7~10 streams from 30 to 5 fps > and it goes around 100 % without transcoding the input (only > downsizing the bitrate and the FPS). > > I'm testing with the command: > time ffmpeg -re -rtsp_transport tcp -i > 'rtsp://something:something@fdsfsdfdf' -t 10 -c:v libx264 -b:v 100k > -maxrate 100k -bufsize 50k -r 5 output2.mp4 > Time output (full output on https://pastebin.com/VTabvgQS): > real 0m19.527s > user 0m2.510s > sys 0m0.102s > > > Problems to solve: > * Can I improve the performance of ffmpeg by compiling it? Need to improving performance of encoder library (libx264 in this case), not ffmpeg itself. > * They are some guidelines to improve performance? This may be outdated, because I've tested it several years ago, but openh264 library (-c:v libopenh264) is about 4x faster than libx264 (with no extra parameters given). Do you have particular reason to stick with h264 compression? msmpeg4 (aka divx ?) is about 7x faster. > Thanks for all! > _______________________________________________ > ffmpeg-user mailing list > [email protected] > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
