Convert mp4 to mpt with lower quality - ffmpeg

i need to convert videos from .mp4 to .mp4 (only videos that are disproportionate between quality and size), I've tried with ffmpeg and mencoder, but can not play with fwplayer, any ideas??.

Try using MeGUI, it has presets for low quality exporting for Flash and such.

Related

ffmpeg transparent HVEC video from alpha matte and color video

I have an alpha.mp4 (alpha matte video) and a color.mp4 (color video). How do I use ffmpeg to make a transparent HVEC (.mov) video?
I can combine with ffmpeg to make a .webm file following the instruction here:
https://www.unscreen.com/api under "Convert unpacked Pro Bundle to WEBM video with transparency"
I have a newer mac and should be able to use HVEC_videotoolbox from either these 2 videos or the .webm file created.
The closest I found was this which seems to generate a corrupt video that cannot be viewed in safari. Use FFmpeg to generate a movie with alpha channel from separate video and fill movies? but

How to encode HDR10+(or Dolby vision) videos to HDR video? (In FFmpeg)

I downloaded HDR10+(or Dolby vision) videos from YouTube.
Now I want to check the quality difference.
Although I don't have enough good HW display monitor,
I want to convert HDR10+(Dolby vision) video --> to HDR video.
(I heard that Dolby vision is better colors than HDR video.)
Can you share the command?
Thanks in advance.
I searched some ffmpeg command, and I found some command that converts HDR video to SDR video.
But there is no ffmpeg command HDR10+ video to HDR video.

How to keep video codec as original one after adding images?

I use ffmpeg to add subtitles to video.
Subtitles are created by imagemagick and I use filter_complex to add these images to video.
And I want to keep original video codec.
Please help me.

FFmpeg poor quality encoded MPEG-4 video

Have adapted FFmpeg sample muxing.c under Windows 7 to write MP4 files from video camera RGB data.
Using muxing.c default bit_rate=400000.
Am not setting global_quality.
Resultant MP4 is poor quality, highly pixelated.
Original raw images in video camera are sharp.
What values should I use for bit_rate? Do I have to also set rc_max_rate?
What values should I use for global_quality? Do I have to set any flags to enable use of global_quality?
Is bit_rate versus global_quality an either/or situation? Or can both be useful in adjusting quality?
Thanks for your time.

ffmpeg picture slideshow with audio

I'm trying to make a batch of videos for uploading to youtube. My emphasis is on the audio (mostly MP3, with some WMA). I have several image files that need to be picked up at random to go with the audio (ie) display an image for 5 seconds before showing the next. I want the video to stop when the audio stream ends. How should I use ffmpeg to achieve this ?
Ref:
http://trac.ffmpeg.org/wiki/Create%20a%20video%20slideshow%20from%20images

Resources