July 2006 - ffmpeg-user - lists.ffmpeg.org

questions about performance tuning and enable-shared
by reid.vail＠mci.com 13 Sep '06

13 Sep '06

Shown below is the ffmpeg version I'm running. I have two questions about different issues: 1) performance tuning and 2) using --enable-shared. --------------------------------------------------------------------------- reid at linux:~/FFMpeg-20050519/FFMpeg-20050519> ffmpeg -version ffmpeg version 0.4.9-pre1, build 4755, Copyright (c) 2000-2004 Fabrice Bellard configuration: --prefix=/usr --enable-mp3lame --enable-gpl built on May 18 2005 22:26:04, gcc: 3.3.4 (pre 3.3.5 20040809) ffmpeg 0.4.9-pre1 libavcodec 4755 libavformat 4624 ---------------------------------------------------------------------------- 1) Regarding performance tuning, I wonder if I well get better performance from ffmpeg if I ./configure it with the cpu info I'm using? I have an AMD x86_64. Should I use the --tune option, and would the syntax be --tune=x86_64, or some other syntax. What might that be, please? 2) When I have run ./configure with --enable-shared the Make bombs. Should I be adding some other options or switches (meaning..is it something I'm doing wrong?) and can you tell me what it is I need to do or is ffmpeg just not ready for --enable-shared with x86_64? Thanks Reid ______________________________________________________________________ This e-mail has been scanned by MCI Managed Email Content Service, using Skeptic? technology powered by MessageLabs. For more information on MCI's Managed Email Content Service, visit http://www.mci.com. ______________________________________________________________________

2 1

ffmpeg wmv codec problem
by luis＠friendlycomputers.com 24 Aug '06

24 Aug '06

Hello: I have a problem with wmv coded in ffmpeg I need some help because I can't find how I can install this codec in my linux sever Thanks Luis

5 5

Wide Characters
by jonathan.beavers＠gmail.com 18 Aug '06

18 Aug '06

I'm trying to pass UTF-8 character strings to a stripped-down ffmpeg binary I built, but I can't seem to get av_open_input_file to work. This isn't too surprising, but I'm kind of at the end of my rope trying to figure out how to play with files that have non-latin characters in the name. Simply renaming the desired files isn't exactly suitable, unfortunately. Is there some kind of really obvious solution that I am missing? Thanks, Jon

2 5

Choice of a low-CPU codec
by nicolas.george＠ens.fr 05 Aug '06

05 Aug '06

I am trying to write a simple video-player program to run on a Compaq iPaq H3800, which is a PDA. It has good sound output for headphones, a 6x8 cm (320x240) screen, can last more than two hours even with screen backlight on and busy CPU, and can read big SD memory cards, so it is not absurd to think about using it to watch a movie during a train ride for example. (On my last train ride, a fellow traveller started watching a movie on his cell phone, with a screen at least five time smaller, so...) Anyway, the problem is CPU power: it is a 200 MHz StrongARM, and obviously no GPU, and no FPU either. I did the following benchmarks: - Decoding MP3 (128kbps, 44.1kHz stereo) with MAD takes 180 ms per second (decoding Vorbis using Tremor takes more). - Converting a single frame from YUV40P to the native RGB565 of the framebuffer (using img_convert) takes 18 ms. - Decoding of MPEG4 (XviD with fixed quantizer 6) takes also an average 18 ms per frame. Which means it is possible to play at 22 frame per second, and probably a full 29.97 fps for movies (which will probably only be 320x180 or 320x136). Under those circumstances, decoding wider images and on-the-fly scaling are out of the question, and the video must be transcoded for the occasion. Which leads to the question: which codec to use? Is there a codec with a quality similar to the one of MPEG4, maybe a bitrate a bit larger, but for which decoding require less CPU? And, if there is not, are there options for MPEG4 that can reduce decode-time CPU usage, even at the cost of some quality or bitrate? Any advice would be appreciated. Regards, -- Nicolas George

3 4

Flash 8 FLV?
by jtugman＠mitre.org 03 Aug '06

03 Aug '06

It is my understanding that FFmpeg does nto currently export to Flash 8. Is there any word on if someone is currently working on this?

3 2

Delphi translation
by fernando.afonso＠co.sapo.pt 01 Aug '06

01 Aug '06

Zinetz Victor, Please, can you send me the avcodec, avutil and avformat header translation? Thanks, Fernando Afonso fernando.afonso at co.sapo.pt

2 1

Delphi headers for avcodec and avformat?
by fernando.afonso＠co.sapo.pt 31 Jul '06

31 Jul '06

Does anyone translate avcodec.h and avformat.h to Delphi pas?! Fernando Afonso fernando.afonso at co.sapo.pt

1 0

ffmpeg and mplayer - installing new codecs
by ffmpeg＠tompercival.com 31 Jul '06

31 Jul '06

Hi I have installed ffmpeg and mplayer on my system and have followed the instructions for installing the essential codecs package - mplayer is successfully taking jpeg stills from .rm and .wmv files - i did this by copying them to /usr/lib/win32/. I also need to get these to work in ffmpeg but cant find any reference to where ffmpeg keeps similar codec files. I want ffmpeg to handle the conversion into .flv. Can anyone please help? Thanks in advance Tom

2 1

Please DLL
by fernando.afonso＠co.sapo.pt 31 Jul '06

31 Jul '06

Can anyone send me FFMPeg avcodec and avformat DLL with h Headers? Please?! Thanks, Fernando Afonso fernando.afonso at co.sapo.pt

1 0

Encoding flash video for my website.
by betastars＠gmail.com 31 Jul '06

31 Jul '06

Greetings, I am attemping to setup a website for my family. I want to allow family members to easily upload and watch videos. After looking around it seems flash video is the best choice for this task. I have the transcoding process automated already thanks to ffmpeg. The only problem now is the quality of the videos. Every video I have tried has been very blocky compared to videos on youtube which are using flash video as well. I would really like to match youtube's quality if possible. Currently I am using this line: ffmpeg -i $vin -s 320x240 -r 24 -b 256 -bufsize 50 -minrate 0 -maxrate 300 -ar 22050 -ab 64 $vout I am a novice when it comes to video encoding. Can anyone tell me what I am doing wrong, and how to fix it? Any advice is appreciated.

2 1