SnesLab - User contributions [en]

Bit Rate Reduction

2019-07-24T22:33:02Z

Molive:

'''Bit Rate Reduction''' or '''BRR''' is the name given to the audio compression method used on the [[SPC700]] sound chip used in the [[SNES]], as well as the audio processors of a few other consoles. It is a form of '''ADPCM'''.

BRR uses blocks of 9 bytes, which decompress to create 16 16-bit samples. This gives a compression ratio of 32:9.
Aside from using a form of streaming to the echo buffer, this is the only sound format the APU can play back (it cannot play uncompressed samples).

== Format ==

Each block is made of 9 bytes. Of these there is a header byte, and 8 data bytes. The header contains some flags, and the 8 data bytes contain 16 nibbles of data, one for each sample.
=== header ===
- ssssffle
s - The shift amount for the block. This is a number between 0 and 12, to which each nibble is shifted left. The exact formula is
sample = (nibble _shift left_ shift) _shift right_ 1
This means that a value of 12 will shift left 11, and a value of 0 will actually shift right 1. Values between 13 and 15 perform the formula
sample = (nibble _shift right_ 3) _shift left_ 11
f - The filter used on the sample. After being decoded through the shift, it is put through a "filter". There are 4 available on the SNES (more on the PS1). The filters are (with the output from the shift referred to as the "current sample")
Filter 0: no effect is applied, current sample is output.
Filter 1: output is the current sample, plus the previous times 0.9375.
Filter 2: output is the current sample, plus the previous times 1.90625 minus the one before that times 0.9375
Filter 3: output is the current sample, plus the previous times 1.796875 minus the one before that times 0.8125
e - If this bit is set, it is the end of the sample. The relevant bit in ENDx is set, and either the sample instantaneously stops or loops.

l - If this bit is set, when the end of the sample is hit the DSP jumps to the loop point and continues processing. ENDx is still set.
If both of the above flags are not set, then the next block is decoded and output.
=== data ===
- 11112222
1 - first sample

2 - second sample
In the second byte it is the third and fourth, and so on.
== Other notes ==
If the output of the sample is larger that +3FFF or smaller than -4000 then the sample will under/overflow to the other side. This will not happen more than once - after one under/overflow it starts to clip instead of wrapping.

A good idea is to start a sample with a filter 0 block, because at that point the previous and previous previous samples are undefined.

User:Molive/BRR Compression

2019-07-24T22:28:40Z

Molive: Molive moved page User:Molive/BRR Compression to BRR Compression

#REDIRECT [[BRR Compression]]

Bit Rate Reduction

2019-07-24T22:28:40Z

Molive: Molive moved page User:Molive/BRR Compression to BRR Compression

'''Bit Rate Reduction''' or '''BRR''' is the name given to the audio compression method used on the [[SPC700]] sound chip used in the [[SNES]], as well as the audio processors of a few other consoles. It is a form of '''ADPCM'''.

BRR uses blocks of 9 bytes, which decompress to create 16 16-bit samples. This gives a compression ratio of 32:9.
Aside from using a form of streaming to the echo buffer, this is the only sound format the APU can play back (it cannot play uncompressed samples).

== Format ==

Each block is made of 9 bytes. Of these there is a header byte, and 8 data bytes. The header contains some flags, and the 8 data bytes contain 16 nibbles of data, one for each sample.
=== header ===
- ssssffle
s - The shift amount for the block. This is a number between 0 and 12, to which each nibble is shifted left. The exact formula is
sample = (nibble _shift left_ shift) _shift right_ 1
This means that a value of 12 will shift left 11, and a value of 0 will actually shift right 1. Values between 13 and 15 perform the formula
sample = (nibble _shift right_ 3) _shift left_ 11
f - The filter used on the sample. After being decoded through the shift, it is put through a "filter". There are 4 available on the SNES (more on the PSX). The filters are (with the output from the shift referred to as the "current sample")
Filter 0: no effect is applied, current sample is output.
Filter 1: output is the current sample, plus the previous times 0.9375.
Filter 2: output is the current sample, plus the previous times 1.90625 minus the one before that times 0.9375
Filter 3: output is the current sample, plus the previous times 1.796875 minus the one before that times 0.8125
e - If this bit is set, it is the end of the sample. The relevant bit in ENDx is set, and either the sample instantaneously stops or loops.

l - If this bit is set, when the end of the sample is hit the DSP jumps to the loop point and continues processing. ENDx is still set.
If both of the above flags are not set, then the next block is decoded and output.
=== data ===
- 11112222
1 - first sample

2 - second sample
In the second byte it is the third and fourth, and so on.
== Other notes ==
If the output of the sample is larger that +3FFF or smaller than -4000 then the sample will under/overflow to the other side. This will not happen more than once - after one under/overflow it starts to clip instead of wrapping.

A good idea is to start a sample with a filter 0 block, because at that point the previous and previous previous samples are undefined.

Bit Rate Reduction

2019-07-24T22:28:05Z

Molive:

'''Bit Rate Reduction''' or '''BRR''' is the name given to the audio compression method used on the [[SPC700]] sound chip used in the [[SNES]], as well as the audio processors of a few other consoles. It is a form of '''ADPCM'''.

BRR uses blocks of 9 bytes, which decompress to create 16 16-bit samples. This gives a compression ratio of 32:9.
Aside from using a form of streaming to the echo buffer, this is the only sound format the APU can play back (it cannot play uncompressed samples).

== Format ==

Each block is made of 9 bytes. Of these there is a header byte, and 8 data bytes. The header contains some flags, and the 8 data bytes contain 16 nibbles of data, one for each sample.
=== header ===
- ssssffle
s - The shift amount for the block. This is a number between 0 and 12, to which each nibble is shifted left. The exact formula is
sample = (nibble _shift left_ shift) _shift right_ 1
This means that a value of 12 will shift left 11, and a value of 0 will actually shift right 1. Values between 13 and 15 perform the formula
sample = (nibble _shift right_ 3) _shift left_ 11
f - The filter used on the sample. After being decoded through the shift, it is put through a "filter". There are 4 available on the SNES (more on the PSX). The filters are (with the output from the shift referred to as the "current sample")
Filter 0: no effect is applied, current sample is output.
Filter 1: output is the current sample, plus the previous times 0.9375.
Filter 2: output is the current sample, plus the previous times 1.90625 minus the one before that times 0.9375
Filter 3: output is the current sample, plus the previous times 1.796875 minus the one before that times 0.8125
e - If this bit is set, it is the end of the sample. The relevant bit in ENDx is set, and either the sample instantaneously stops or loops.

l - If this bit is set, when the end of the sample is hit the DSP jumps to the loop point and continues processing. ENDx is still set.
If both of the above flags are not set, then the next block is decoded and output.
=== data ===
- 11112222
1 - first sample

2 - second sample
In the second byte it is the third and fourth, and so on.
== Other notes ==
If the output of the sample is larger that +3FFF or smaller than -4000 then the sample will under/overflow to the other side. This will not happen more than once - after one under/overflow it starts to clip instead of wrapping.

A good idea is to start a sample with a filter 0 block, because at that point the previous and previous previous samples are undefined.

Bit Rate Reduction

2019-07-24T22:20:57Z

Molive:

'''Bit Rate Reduction''' or '''BRR''' is the name given to the audio compression method used on the [[SPC700]] sound chip used in the [[SNES]], as well as the audio processors of a few other consoles. It is a form of '''ADPCM'''.

BRR uses blocks of 9 bytes, which decompress to create 16 16-bit samples. This gives a compression ratio of 32:9.
Aside from using a form of streaming to the echo buffer, this is the only sound format the APU can play back (it cannot play uncompressed samples).

== Format ==

Each block is made of 9 bytes. Of these there is a header byte, and 8 data bytes. The header contains some flags, and the 8 data bytes contain 16 nibbles of data, one for each sample.
=== header ===
- ssssffle
s - The shift amount for the block. This is a number between 0 and 12, to which each nibble is shifted left. The exact formula is
sample = (nibble _shift left_ shift) _shift right_ 1
This means that a value of 12 will shift left 11, and a value of 0 will actually shift right 1. Values between 13 and 15 perform the formula
sample = (nibble _shift right_ 3) _shift left_ 11
f - The filter used on the sample. After being decoded through the shift, it is put through a "filter". There are 4 available on the SNES (more on the PSX). The filters are (with the output from the shift referred to as the "current sample")
Filter 0: no effect is applied, current sample is output.
Filter 1: output is the current sample, plus the previous times 0.9375.
Filter 2: output is the current sample, plus the previous times 1.90625 minus the one before that times 0.9375
Filter 3: output is the current sample, plus the previous times 1.796875 minus the one before that times 0.8125
e - If this bit is set, it is the end of the sample. The relevant bit in ENDx is set, and either the sample instantaneously stops or loops.
l - If this bit is set, when the end of the sample is hit the DSP jumps to the loop point and continues processing. ENDx is still set.
If both of the above flags are not set, then the next block is decoded and output.
=== data ===
- 11112222
1 - first sample
2 - second sample
In the second byte it is the third and fourth, and so on.
== Other notes ==
If the output of the sample is larger that +3FFF or smaller than -4000 then the sample will under/overflow to the other side. This will not happen more than once - after one under/overflow it starts to clip instead of wrapping.

A good idea is to start a sample with a filter 0 block, because at that point the previous and previous previous samples are undefined.

Bit Rate Reduction

2019-07-24T22:19:43Z

Molive: add the rest of the file

'''Bit Rate Reduction''' or '''BRR''' is the name given to the audio compression method used on the [[SPC700]] sound chip used in the [[SNES]], as well as the audio processors of a few other consoles. It is a form of '''ADPCM'''.

BRR uses blocks of 9 bytes, which decompress to create 16 16-bit samples. This gives a compression ratio of 32:9.
Aside from using a form of streaming to the echo buffer, this is the only sound format the APU can play back (it cannot play uncompressed samples).

== Format ==

Each block is made of 9 bytes. Of these there is a header byte, and 8 data bytes. The header contains some flags, and the 8 data bytes contain 16 nibbles of data, one for each sample.
=== header ===
- ssssffle
s - The shift amount for the block. This is a number between 0 and 12, to which each nibble is shifted left. The exact formula is
sample = (nibble _shift left_ shift) _shift right_ 1
This means that a value of 12 will shift left 11, and a value of 0 will actually shift right 1. Values between 13 and 15 perform the formula
sample = (nibble _shift right_ 3) _shift left_ 11
f - The filter used on the sample. After being decoded through the shift, it is put through a "filter". There are 4 available on the SNES (more on the PSX). The filters are (with the output from the shift referred to as the "current sample")
Filter 0: no effect is applied, current sample is output.
Filter 1: output is the current sample, plus the previous times 0.9375.
Filter 2: output is the current sample, plus the previous times 1.90625 minus the one before that times 0.9375
Filter 3: output is the current sample, plus the previous times 1.796875 minus the one before that times 0.8125
e - If this bit is set, it is the end of the sample. The relevant bit in ENDx is set, and either the sample instantaneously stops or loops.
l - If this bit is set, when the end of the sample is hit the DSP jumps to the loop point and continues processing. ENDx is still set.
If both of the above flags are not set, then the next block is decoded and output.
=== data ===
- 11112222
1 - first sample
2 - second sample
In the second byte it is the third and fourth, and so on.
== Other notes ==
If the output of the sample is larger that +3FFF or smaller than -4000 then the sample will under/overflow to the other side. This will not happen more than once - after one under/overflow it starts to clip instead of wrapping.

A good idea is to start a sample with a filter 0 block, because at that point the previous and previous previous samples are undefined.

Bit Rate Reduction

2019-05-20T14:57:07Z

Molive: create draft of brr compression page

'''Bit Rate Reduction''' or '''BRR''' is the name given to the audio compression method used on the [[SPC700]] sound chip used in the [[SNES], as well as the audio processors of a few other consoles. It is a form of '''ADPCM'''.

BRR uses blocks of 9 bytes, which decompress to create 16 16-bit samples. This gives a compression ratio of 32:9.
Aside from using a form of streaming to the echo buffer, this is the only sound format the APU can play back (it cannot play uncompressed samples).

User:Molive/Retro Game Mechanics Explained

2019-05-20T09:58:12Z

Molive: Molive moved page User:Molive/Retro Game Mechanics Explained to Retro Game Mechanics Explained: Move completed page

#REDIRECT [[Retro Game Mechanics Explained]]

Retro Game Mechanics Explained

2019-05-20T09:58:12Z

Molive: Molive moved page User:Molive/Retro Game Mechanics Explained to Retro Game Mechanics Explained: Move completed page

'''Retro Game Mechanics Explained''' (often shortened to ''RG Mech Ex'' ) is a YouTube channel run by [[DotsAreCool]] which is devoted to in depth breakdowns and explainations of old game console hardware and software. The channel is probably best known for the long running series ''Super NES Features'' , where every part of the [[SNES]] hardware is explained in great detail with helpful diagrams and animations. The channel has also covered topics including the NES and the GameBoy, as well as other systems and concepts.

== Super NES Features episodes ==
=== Released episodes ===
* 1. [https://www.youtube.com/watch?v=57ibhDU2SAI Graphics and Palettes]
* 1b. [https://www.youtube.com/watch?v=nk_TbDO5QpE Graphics and Palettes (3d representation)]
* 2. [https://www.youtube.com/watch?v=sheOZ-Dlleo Objects]
* 3. [https://www.youtube.com/watch?v=uRjf8ZP6rs8 Backgrounds and Rendering]
* 3b. [https://www.youtube.com/watch?v=zcoU6-9_fDM Color Math]
* 4. [https://www.youtube.com/watch?v=5SBEAZIfDAg SNES Background Modes 0-6]
* 4b. [https://www.youtube.com/watch?v=AnEuk8Vj3w0 Higher Resolutions]
* 5. [https://www.youtube.com/watch?v=3FVN_Ze7bzw SNES Background Mode 7]
* 6. [https://www.youtube.com/watch?v=Q8ph2OVqZeM Lag & Blanking]
* 7. [https://www.youtube.com/watch?v=K7gWmdgXPgk DMA & HDMA]
* 8. [https://www.youtube.com/watch?v=2Dw7NFm1ZfY Controllers]
=== Planned episodes ===
* 9. Memory Mapping and Vectors
* 10. ARAM & SPC700
* 11. Hardware Registers

== External Links ==
* [https://www.youtube.com/channel/UCwRqWnW5ZkVaP_lZF7caZ-g Youtube Channel]
* [https://www.patreon.com/rgmechex Patreon]
* [https://twitter.com/RetroGameMechEx Twitter]

Retro Game Mechanics Explained

2019-05-20T09:57:06Z

Molive: Added episode list

SNES

2019-05-19T22:22:25Z

Molive: I just realized there is no page for the SNES. huh.

#REDIRECT [[Super Nintendo Entertainment System]]

Retro Game Mechanics Explained

2019-05-19T22:17:06Z

Molive: Created Retro Game Mechanics Explained draft page

User:Molive

2019-05-19T17:01:57Z

Molive: Created page with "= Hello = I'm [https://demozoo.org/sceners/72284/ Molive], the [https://en.wikipedia.org/wiki/Demoscene demoscener]. I like to create demos for the SNES, and also its Extens..."

= Hello =
I'm [https://demozoo.org/sceners/72284/ Molive], the [https://en.wikipedia.org/wiki/Demoscene demoscener]. I like to create demos for the SNES, and also its [[Extension Chips]].
This means I mainly focus on creating things which look really cool, are non-interactive and last up to 8 minutes.
I'm part of the demogroups [https://demozoo.org/groups/1433/ Slipstream] and [https://demozoo.org/groups/2883/ Titan].

...cool

Lunar Magic

2019-05-19T16:29:16Z

Molive: Added link to the Lunar Magic homepage

'''Lunar Magic''' is a level editor created by FuSoYa for Super Mario World. The interface runs on Microsoft Windows and allows people to create custom graphics and edit levels and the world map.

== External Links ==
* [https://fusoya.eludevisibility.org/lm/index.html Official Website]

[[Category:Super Mario World]] [[Category:Super Mario World Hacking Tools]] [[Category:Hacking Tools]] [[Category:Level Editors]] [[Category:Graphic Editors]] [[Category:Overworld Editors]]