[Michael Rampe]

[Volker Bradley] “My screencasts are not as distinct as others that I see on youtube. Can you give me some suggestions?”

It seems that all of you examples are being scaled in different ways, either by yourself, or by youtube.

To get the best results for screen capture material, keep the pixels intact without scaling.

Youtube HD is the same as ‘normal’ HD and comes in two sizes.
1920×1080 (1080p)
1280×720 (720p)

Seeing that your monitor has a max resolution of 1680×1050, I would aim for close to the 1280×720 size for CAPTURE and then CROP to 1280×720 for delivery. This will ensure that no scaling is done on the pixels and provide a crisp output.

For 1080p you might want to get a new monitor which supports a higher res. One of my monitors will do 1920×1200 which can have 120 pixels cropped from the top and/or bottom to provide a full HD unscaled output.

Michael

[Michael Rampe]

[Mo Paul] “How do I get a raw file in good quality?”

For an uncompressed AVI example, see this post:
https://forums.creativecow.net/readpost/291/224

Michael

[Michael Rampe]

try:

ffmpeg -i input.mov -pix_fmt yuvj422p -acodec pcm -vcodec rawvideo -y output.avi

Michael

[Michael Rampe]

[johan wadman] “My guess is that Samsung TV don’t care about the PAR 4:3 and uses PAR 1:1 instead. So I believe I need to convert 1440×1080 DAR 16:9,PAR4:3 to 1920×1080 DAR 16:9, PAR 1:1 ?
The question is then how do I do that with ffmpeg???”

I agree. since the Samsung device is not respecting the container aspect flag, you will need to re-compress the stream instead of using -vcodec copy.

As you have quite a high bitrate original, you will need to specify that.

one pass example:
ffmpeg -i 00001.MTS -vcodec libx264 -vpre medium -b 11000k -s 1920×1080 -aspect 16:9 -acodec libmp3lame -ab 256k output.mp4

two pass example:
ffmpeg -i 00001.MTS -vcodec libx264 -vpre medium_firstpass -b 11000k -bt 11000k -s 1920×1080 -aspect 16:9 -an -pass 1 /dev/null && ffmpeg -i 00001.MTS -vcodec libx264 -vpre medium -b 11000k -bt 11000k -s 1920×1080 -aspect 16:9 -acodec libmp3lame -ab 256k -pass 2 output.mp4

Depending on the content, you should be able to get acceptable quality at a lower bitrate so do some experiments.

Michael

[Michael Rampe]

If it is one stereo “stream” it is not currently possible.

If there are two discrete mono “streams”, it is possible with the map command.

To find out which you have, perform an input read and post the results. (eg. ffmpeg -i yourfile.mp4)

Michael

[Michael Rampe]

try double quotes “” instead of single quotes ”

Michael

[Michael Rampe]

please post the output including error messages.

Michael

[Michael Rampe]

[coco serujil] “I would like to use FFmpeg to grab still frames from video files. i’m only interested in H264 encoded videos”

This works for me.

ffmpeg -vframes 1 -ss 10 -i default.mp4 -f image2 -vcodec mjpeg frame%d.jpg

“-vframes 1” means only render one frame.
“-ss 10” means pull the frame at 10 seconds.
This was tested with H.264 footage.

Michael

[Michael Rampe]

A little bit of research shows that PCM is not supported in the mpg container format.

https://en.wikipedia.org/wiki/Comparison_of_container_formats

Can you use another type of container? what is your purpose?

Michael

[Michael Rampe]

I think your problem is that you are using -vcopy which, by its nature, does not process the video stream and hence does not change the aspect ratio in the stream. .mpg is an old and limited container in regards to this matter. .mp4 as in your example can store the aspect ratio in the container and works.

[Pete Page] “the ratio remains unchanged -still 4:3”
This is the source aspect ratio which means the display aspect is probably not being held by the container. Do a header read on the mpg output and post the result. (ffmpeg -i slowoutputr.mpg)

Michael