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Diffstat (limited to 'sound/oss/emu10k1/passthrough.h')
| -rw-r--r-- | sound/oss/emu10k1/passthrough.h | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/sound/oss/emu10k1/passthrough.h b/sound/oss/emu10k1/passthrough.h new file mode 100644 index 000000000000..420cc9784251 --- /dev/null +++ b/sound/oss/emu10k1/passthrough.h @@ -0,0 +1,99 @@ +/* + ********************************************************************** + * passthrough.h -- Emu10k1 digital passthrough header file + * Copyright (C) 2001 Juha Yrjl <jyrjola@cc.hut.fi> + * + ********************************************************************** + * + * Date Author Summary of changes + * ---- ------ ------------------ + * May 15, 2001 Juha Yrjl base code release + * + ********************************************************************** + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, + * USA. + * + ********************************************************************** + */ + +#ifndef _PASSTHROUGH_H +#define _PASSTHROUGH_H + +#include "audio.h" + +/* number of 16-bit stereo samples in XTRAM buffer */ +#define PT_SAMPLES 0x8000 +#define PT_BLOCKSAMPLES 0x400 +#define PT_BLOCKSIZE (PT_BLOCKSAMPLES*4) +#define PT_BLOCKSIZE_LOG2 12 +#define PT_BLOCKCOUNT (PT_SAMPLES/PT_BLOCKSAMPLES) +#define PT_INITPTR (PT_SAMPLES/2-1) + +#define PT_STATE_INACTIVE 0 +#define PT_STATE_ACTIVATED 1 +#define PT_STATE_PLAYING 2 + +/* passthrough struct */ +struct pt_data +{ + u8 selected, state, spcs_to_use; + int intr_gpr, enable_gpr, pos_gpr; + u32 blocks_played, blocks_copied, old_spcs[3]; + u32 playptr, copyptr; + u32 prepend_size; + u8 *buf; + u8 ac3data; + + char *patch_name, *intr_gpr_name, *enable_gpr_name, *pos_gpr_name; + + wait_queue_head_t wait; + spinlock_t lock; +}; + +/* + Passthrough can be done in two methods: + + Method 1 : tram + In original emu10k1, we couldn't bypass the sample rate converters. Even at 48kHz + (the internal sample rate of the emu10k1) the samples would get messed up. + To over come this, samples are copied into the tram and a special dsp patch copies + the samples out and generates interrupts when a block has finnished playing. + + Method 2 : Interpolator bypass + + Creative fixed the sample rate convert problem in emu10k1 rev 7 and higher + (including the emu10k2 (audigy)). This allows us to use the regular, and much simpler + playback method. + + + In both methods, dsp code is used to mux audio and passthrough. This ensures that the spdif + doesn't receive audio and pasthrough data at the same time. The spdif flag SPCS_NOTAUDIODATA + is set to tell + + */ + +// emu10k1 revs greater than or equal to 7 can use method2 + +#define USE_PT_METHOD2 (card->is_audigy) +#define USE_PT_METHOD1 !USE_PT_METHOD2 + +ssize_t emu10k1_pt_write(struct file *file, const char __user *buf, size_t count); + +int emu10k1_pt_setup(struct emu10k1_wavedevice *wave_dev); +void emu10k1_pt_stop(struct emu10k1_card *card); +void emu10k1_pt_waveout_update(struct emu10k1_wavedevice *wave_dev); + +#endif /* _PASSTHROUGH_H */ |