Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-06-30 16:00:01 +03:00
Code Issues Actions 3 Packages Projects Releases Wiki Activity

added notes

Browse Source
This commit is contained in:
Michaël Banaan Ananas 2013-12-02 12:57:40 +00:00
parent 735a38f629
commit 9fe2460c65
1 changed files with 15 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
src/emu/sound/ymz770.c
View File

@ -5,6 +5,15 @@
Emulation by R. Belmont
AMM decode by Olivier Galibert
-----
TODO:
- A lot of unimplemented features, even simple ones like panning,
these should be added once we find out any software that uses it.
- Sequencer is very preliminary
- What does channel ATBL mean?
- Is YMZ774(and other variants) the same family as this chip?
What are the differences?
***************************************************************************/
#include "emu.h"
@ -39,8 +48,8 @@ void ymz770_device::device_start()
{
// create the stream
m_stream = machine().sound().stream_alloc(*this, 0, 2, 16000, this);
m_rom_base = device().machine().root_device().memregion(":ymz770")->base();
m_rom_limit = device().machine().root_device().memregion(":ymz770")->bytes() * 8;
m_rom_base = *region();
m_rom_limit = region()->bytes() * 8;
for (int i = 0; i < 8; i++)
{
@ -119,7 +128,7 @@ void ymz770_device::sound_stream_update(sound_stream &stream, stream_sample_t **
{
if (m_channels[ch].is_seq_playing)
{
if (m_channels[ch].seqdelay != 0)
if (m_channels[ch].seqdelay > 0)
{
m_channels[ch].seqdelay--;
}
@ -155,7 +164,7 @@ void ymz770_device::sound_stream_update(sound_stream &stream, stream_sample_t **
{
if (m_channels[ch].output_remaining > 0)
{
mix += (m_channels[ch].output_data[m_channels[ch].output_ptr++]*2*m_channels[ch].volume);
mix += (m_channels[ch].output_data[m_channels[ch].output_ptr++]*m_channels[ch].volume);
m_channels[ch].output_remaining--;
}
else
@ -179,12 +188,7 @@ retry:
if (m_channels[ch].is_playing)
{
int sample_rate, channel_count;
if (!m_channels[ch].decoder->decode_buffer(m_channels[ch].pptr,
m_rom_limit,
m_channels[ch].output_data,
m_channels[ch].output_remaining,
sample_rate,
channel_count))
if (!m_channels[ch].decoder->decode_buffer(m_channels[ch].pptr, m_rom_limit, m_channels[ch].output_data, m_channels[ch].output_remaining, sample_rate, channel_count) || m_channels[ch].output_remaining == 0)
{
m_channels[ch].is_playing = !m_channels[ch].last_block; // detect infinite retry loop
m_channels[ch].last_block = true;
@ -195,7 +199,7 @@ retry:
m_channels[ch].output_remaining--;
m_channels[ch].output_ptr = 1;
mix += (m_channels[ch].output_data[0]*2*m_channels[ch].volume);
mix += (m_channels[ch].output_data[0]*m_channels[ch].volume);
}
}
}