author Sam Lantinga <>
Fri, 01 Jun 2018 19:43:53 -0700
changeset 12005 94f3f018d3eb
parent 11811 5d94cb6b24d3
child 12503 806492103856
permissions -rw-r--r--
Fixed bug 4184 - jack audio driver fails in presence of midi ports

Martin Širokov

Launching an SDL application with SDL_AUDIODRIVER=jack, and then calling SDL_OpenAudioDevice() with whatever parameters fails with an error like this one:

SDL_OpenAudioDevice: Couldn't connect JACK ports: SDL:sdl_jack_output_0 => system:midi_playback_1

This happens because JACK_OpenDevice in src/audio/jack/SDL_jackaudio.c blindly tries to connect to all input ports without checking whether they are for audio or midi.

The fix is to check port types and ignore all non audio ports. Also I removed devports field from struct SDL_PrivateAudioData, because it's never really used and removing unused ports from it would be PITA.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2018 Sam Lantinga <>
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 #ifndef SDL_jackaudio_h_
    22 #define SDL_jackaudio_h_
    24 #include <jack/jack.h>
    26 #include "../SDL_sysaudio.h"
    28 /* Hidden "this" pointer for the audio functions */
    29 #define _THIS SDL_AudioDevice *this
    31 struct SDL_PrivateAudioData
    32 {
    33     jack_client_t *client;
    34     SDL_sem *iosem;
    35     float *iobuffer;
    36     jack_port_t **sdlports;
    37 };
    39 #endif /* SDL_jackaudio_h_ */
    41 /* vi: set ts=4 sw=4 expandtab: */