How to make a soundpost

Software:

Stacher
Shutter Encoder

Capturing the segments

1. Paste url in Stacher
2. Use [trim/crop] option and set the start and end times
3. Choose the quality (I use best video+best audio)
4. Download the segment
5. Rename the segment, otherwise I won't allow you to download another one

Once all the segments are done, you can move to Shutter

Demuxing audio

1. Drop all the files
2. Chose [Extract] on the choose function menu, and then [Audio].
3. [Start function]

Encoding

1. Now select [VP9] in the function menu
2. In [audio setting] select [No audio]. You can't avoid this otherwise 4chan won't accept the file.
3. Use [Image Cropping] if you want to do so. If you are going to use all the screen it's recommended to use the [scale] options.
4. Set [Video Bitrate] to best or good. If the final file is over 4mb, 4chan's limit, you will have to chose the [file size] option and put 3mb, as otherwise it will average 4mb and could be over the limit. 2 pass and Max Quality are optional and will make the encoding a lot longer.
5. Start function.

Making the soundposts

1. Drop the audio files to Catbox
2. Open the 4chan sounds window and open the drop list and chose Tools
3. Copy and paste the audio url in [Encode/Decode URL]
4. Copy the result and rename the resulting VP9 video file: name [sound=here goes the url].webm
5. The soundpost is ready to go.