trunk/src/mess/audio/alesis.c
| r17450 | r17451 | |
|---|
| 80 | 80 | if (m_output_active) |
| 81 | 81 | { |
| 82 | 82 | INT16 sample = m_samples[m_cur_sample++]; |
| 83 | int count = 0; |
| 83 | 84 | |
| 84 | | if (sample == -128 && m_shift) |
| 85 | while (sample == -128 |
| 85 | 86 | { |
| 86 | | /* |
| 87 | | The HR-16 seems to use a simple scheme to generate 16-bit samples from its 8-bit sample ROMs. |
| 88 | | When the sound starts the 8-bit sample is sent to the most significant bits of the DAC and every |
| 89 | | time a -1 sample is found the data is shifted one position to right. |
| 90 | | */ |
| 91 | | sample = m_samples[m_cur_sample++]; |
| 92 | | m_shift--; |
| 87 | count++; |
| 93 | 88 | |
| 94 | | if (LOG) logerror("DM3AG '%s' shift: %02x\n", tag(), m_shift); |
| 95 | | } |
| 89 | if (count == 1 && m_shift) |
| 90 | { |
| 91 | /* |
| 92 | The HR-16 seems to use a simple scheme to generate 16-bit samples from its 8-bit sample ROMs. |
| 93 | When the sound starts the 8-bit sample is sent to the most significant bits of the DAC and every |
| 94 | time a -1 sample is found the data is shifted one position to right. |
| 95 | */ |
| 96 | m_shift--; |
| 96 | 97 | |
| 97 | | m_dac->write_signed16((sample << m_shift) + 0x8000); |
| 98 | if (LOG) logerror("DM3AG '%s' shift: %02x\n", tag(), m_shift); |
| 99 | } |
| 98 | 100 | |
| 99 | | // every block ends with three or more -1 samples |
| 100 | | if (m_cur_sample == 0xfffff || (m_samples[m_cur_sample-1] == -128 && m_samples[m_cur_sample] == -128 && m_samples[m_cur_sample+1] == -128)) |
| 101 | | { |
| 102 | | m_output_active = false; |
| 103 | | m_dac->write_signed16(0x8000); |
| 101 | // every block ends with three or more -1 samples |
| 102 | if (m_cur_sample == 0xfffff || count >= 3) |
| 103 | { |
| 104 | m_output_active = false; |
| 105 | sample = 0; |
| 104 | 106 | |
| 105 | | if (LOG) logerror("DM3AG '%s' stop: %d\n", tag(), m_cur_sample-((m_cmd[0]<<12) | (m_cmd[1]<<4) | ((m_cmd[2]>>4) & 0x0f))); |
| 107 | if (LOG) logerror("DM3AG '%s' stop: %d, len: %d\n", tag(), m_cur_sample, m_cur_sample-((m_cmd[0]<<12) | (m_cmd[1]<<4) | ((m_cmd[2]>>4) & 0x0f))); |
| 108 | |
| 109 | break; |
| 110 | } |
| 111 | |
| 112 | sample = m_samples[m_cur_sample++]; |
| 106 | 113 | } |
| 114 | |
| 115 | m_dac->write_signed16((sample << m_shift) + 0x8000); |
| 107 | 116 | } |
| 108 | 117 | } |
| 109 | 118 | |