Mercurial > repos > blastem
diff vgm.c @ 2041:638eb2d25696 mame_interp
Merge from default
author | Michael Pavone <pavone@retrodev.com> |
---|---|
date | Thu, 05 Aug 2021 09:29:33 -0700 |
parents | 327332138c5c |
children |
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--- a/vgm.c Sun May 10 00:16:00 2020 -0700 +++ b/vgm.c Thu Aug 05 09:29:33 2021 -0700 @@ -60,22 +60,33 @@ } } +#include "util.h" static void add_wait(vgm_writer *writer, uint32_t cycle) { - uint64_t delta = cycle - writer->last_cycle; - delta *= (uint64_t)44100; - delta /= (uint64_t)writer->master_clock; + if (cycle < writer->last_cycle) { + //This can happen when a YM-2612 write happens immediately after a PSG write + //due to the relatively low granularity of the PSG's internal clock + //given that VGM only has a granularity of 44.1 kHz ignoring this is harmless + return; + } + uint64_t last_sample = (uint64_t)writer->last_cycle * (uint64_t)44100; + last_sample /= (uint64_t)writer->master_clock; + uint64_t sample = ((uint64_t)cycle + (uint64_t)writer->extra_delta) * (uint64_t)44100; + sample /= (uint64_t)writer->master_clock; + uint32_t delta = sample - last_sample; - uint32_t mclks_per_sample = writer->master_clock / 44100; - writer->last_cycle += delta * mclks_per_sample; + writer->last_cycle = cycle; + writer->extra_delta = 0; writer->header.num_samples += delta; wait_commands(writer, delta); } +static uint8_t last_cmd; void vgm_sn76489_write(vgm_writer *writer, uint32_t cycle, uint8_t value) { add_wait(writer, cycle); uint8_t cmd[2] = {CMD_PSG, value}; + last_cmd = CMD_PSG; fwrite(cmd, 1, sizeof(cmd), writer->f); } @@ -88,6 +99,7 @@ { add_wait(writer, cycle); uint8_t cmd[3] = {CMD_YM2612_0, reg, value}; + last_cmd = CMD_YM2612_0; fwrite(cmd, 1, sizeof(cmd), writer->f); } @@ -95,12 +107,14 @@ { add_wait(writer, cycle); uint8_t cmd[3] = {CMD_YM2612_1, reg, value}; + last_cmd = CMD_YM2612_1; fwrite(cmd, 1, sizeof(cmd), writer->f); } void vgm_adjust_cycles(vgm_writer *writer, uint32_t deduction) { if (deduction > writer->last_cycle) { + writer->extra_delta += deduction - writer->last_cycle; writer->last_cycle = 0; } else { writer->last_cycle -= deduction; @@ -109,6 +123,8 @@ void vgm_close(vgm_writer *writer) { + uint8_t cmd = 0x66; + fwrite(&cmd, 1, sizeof(cmd), writer->f); writer->header.eof_offset = ftell(writer->f) - offsetof(vgm_header, eof_offset); fseek(writer->f, SEEK_SET, 0); fwrite(&writer->header, sizeof(writer->header), 1, writer->f);