diff options
author | Daniel Schürmann <daschuer@mixxx.org> | 2015-12-23 19:52:29 +0100 |
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committer | Daniel Schürmann <daschuer@mixxx.org> | 2015-12-23 19:55:38 +0100 |
commit | a543a4be560f511859d5ec0e2af43b1980e072dc (patch) | |
tree | e294624f8a375f3fd3a68c7ae866da7eac40ec48 /src/controllers/midi/portmidicontroller.h | |
parent | afc8e1d9cd632f91887e016227527d76d48f722f (diff) |
move midi related comments to portmidicontrol.h
Diffstat (limited to 'src/controllers/midi/portmidicontroller.h')
-rw-r--r-- | src/controllers/midi/portmidicontroller.h | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/src/controllers/midi/portmidicontroller.h b/src/controllers/midi/portmidicontroller.h index c3fa462678..213b1b3e5d 100644 --- a/src/controllers/midi/portmidicontroller.h +++ b/src/controllers/midi/portmidicontroller.h @@ -20,12 +20,28 @@ #include <portmidi.h> #include "controllers/midi/midicontroller.h" -// Mixxx completely stops responding to the controller if more than this number -// of messages queue up. Don't lower this (much.) The SCS.1d a 3x Speed device +// Note: +// A standard Midi device runs at 31.25 kbps, with 10 bits / byte +// 1 byte / 320 microseconds +// a usual Midi message has 3 byte which results to +// 1042.6 messages per second +// +// The MIDI over IEEE-1394: +// http://www.midi.org/techspecs/rp27v10spec%281394%29.pdf +// which is also used for USB defines 3 speeds: +// 1 byte / 320 microseconds +// 2 bytes / 320 microseconds +// 3 bytes / 320 microseconds +// which results in up to 3125 messages per second +// if we assume normal 3 Byte messages. +// +// For instants the SCS.1d, uses the 3 x speed +// +// Due to a bug Mixxx completely stops responding to the controller +// if more than this number of messages queue up. Don't lower this (much.) +// The SCS.1d a 3x Speed device // accumulated 500 messages in a single poll during stress-testing. // A midi message contains 1 .. 4 bytes. -// The maximum Midi Speed (3x Speed) is around 3125 messages per second -// if we assume normal 3 Byte messages. // a 1024 messages buffer will buffer ~327 ms Midi-Stream #define MIXXX_PORTMIDI_BUFFER_LEN 1024 |