Getting video files right is not a simple tasks, and most of the time requires the combination of several tools. Depending of your preference (simplicity, tweaking possibilities, ...) the choice is yours.
Handbrake
At the moment my favourite video editing tool, although not the easiest to get in your fingers. It allows detailed finetuning, and once well understood, delivers exactly what you want. It also supports hardware aceleration, which pushes my GPU to maximum encoding support.
PRO
- you can finetune almost everything
- open source
- it works with a queue which allows you to prepare all conversions while it is already converting the current files. It also supports different settings for each file in the queue.
- allows to encode with audio passthrough, resulting in maintaining the audio quality of the original files
- makes maximum use of processor and GPU resources to speed up conversion (on the condition choosing the codecs linked to your graphics card, in my case H.265 NVidia NVEnc. I prefer to set the average bitrate (half of the H.264 bitrate) and peak frame rate to 30 fps
- supports multiple audio & subtitle streams in the resulting file
CON
- it takes some time to get it right
- seems not to be capable to stitch/append files
HD Video convertor Factory Pro
Having choosen this software a few years ago with a lifetime license did have its advantages, taking full benefit of hardware encoding (Nvidia GTX 1060 6GB).
Pro:
- Easy to use
- Option for automated lossless conversion
- Has a lossless H265 mode that typically halves the bitrate compared to H264 files
- Includes youtube download options, screen recording, gif maker, ...
- Allows multiple files to be converted sequentially (using the same export settings).
Con:
- tends to give a 100ms audio synchronisation issue when doing H265 encoding.
- lacks the advanced tweaking options to do proper issue handling (eg. audio sync)
- only supports 1 audio channel for the resulting file
- while converting, the interface is not available for any action
Avidemux
Another personal favourite, especially interesting for lossless trimming / stitching / deleting / appending parts of a video file (use the ffwd/fbackward buttons to jump to keyframes that allow cutting). Lossless because by default the video and audio streams are just copied into the new file. On top of that, it allows lossless audio synchronisation applying and previewing the chosen delay. (I suggest playing around with multiples of 50ms).
Pro
- Simple and intuitive interface
- Fast lossless stitching/cropping/cutting/appending
- Very suited for audio synchronisation corrections
- Supports audio & video tweaking (cropping/volume/...)
Con
- while converting, the interface is not available for any other action
- only supports 1 resulting file simultaneously, but multiple instances CAN run simultaneously, 2 of which can actually share the GPU, and a third instance preparing another movie
MKVToolnix
MKVToolnix is a very special toolkit for specific use cases, but can be extremely useful when you
- want to clean out/order multiple audio tracks in a video file
- extract/insert audio tracks in a video file (eg. after improving/cleaning out audio files)