mpeg

I am currently trying to extract each frame time stamp from an MPEG-4 file that has been recorded using a GoPro. I want the exact time at which the frame has been captured by the camera, to couple that with computer vision algorithms later on. I know that the output framerate is 25 fps. I extracted the pts in different ways using ffmpeg and ffprobe, but they all show way too perfect results for me to believe them. Each frame/packet has a precise, 0.04 sec interal (or 3600 in pts units) which conveniently enough matches a perfect 25 fps. The commands I have used so far are: ffmpeg -i 3_96025

I am trying to figure out how GOP works Consider the uncoded frame sequence: I B B P B B P B B P B B I B B P B B P B I understand what The N(GOP) is, it's 12 if I am counting from Iframe to Iframe. I know what the predicted span is, it's 2. What is the reordered sequence for decoding for these frames? How would you increase random access? How would you increase compression? How do errors creep in? could someone explain it to me the 4 questions. thank you Check out this MPEG compression FAQ , particularly the section "Q. So is each frame predicted from the last frame?" for a more detailed

I'm writing a MPEG-TS file parser and I'm stuck on getting program_numbers and PIDs from the PAT section. I'm using a packet analyser to compare my results. For example, here's a PAT packet 47 40 00 16 00 00 B0 31 00 14 D7 00 00 00 00 E0 10 00 01 E0 24 00 02 E0 25 00 03 E0 30 00 04 E0 31 00 1A E0 67 00 1C E0 6F 43 9D E3 F1 43 A3 E3 F7 43 AC E4 00 C3 69 A6 D8 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF

I need to be able to programmatically transcode mpeg-2 files to .mp4, .mp3, .wmv, .rm (optional), and .flv (optional), and hopefully generate a thumbnail as well. I found the Java Media Framework, but it frankly looks pretty crappy. This will be running a Linux server, so I could shell out to ffmpeg using Commons Exec - does ffmpeg do everything I need to do? FFmpeg seems pretty daunting, which is why I'm having trouble finding this information, but it definitely seems to be a jack-of-all-trades. Any suggestions? Ffmpeg is the best and easiest. To output/convert video: ffmpeg -i {input}.ext -r

I'm trying to interleave MPEG-TS segments but failing. One set of segments was actually captured using the built in camera in the laptop, then encoded using FFMPEG with the following command: ffmpeg -er 4 -y -f video4linux2 -s 640x480 -r 30 -i %s -isync -f mpegts -acodec libmp3lame -ar 48000 -ab 64k -s 640x480 -vcodec libx264 -fflags +genpts -b 386k -coder 0 -me_range 16 -keyint_min 25 -i_qfactor 0.71 -bt 386k -maxrate 386k -bufsize 386k -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -aspect 640:480 And the other one is an avi file that was encoded using the following command: fmpeg -er 4 -y -f avi -s