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pcecd: minor timing adjustments

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Minor timing adjustments
This commit is contained in:
David Shadoff
2020-05-11 03:38:23 -04:00
committed by GitHub
parent e6602fc569
commit 19b3e04b05
3 changed files with 21 additions and 9 deletions
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10
support/pcecd/pcecd.cpp
View File

@@ -24,8 +24,14 @@ void pcecd_poll()
if (CheckTimer(poll_timer))
{
poll_timer += 13 + (!adj ? 1 : 0);
if (++adj >= 3) adj = 0;
if ((!pcecdd.latency) && (pcecdd.state == PCECD_STATE_READ)) {
poll_timer += 16 + ((adj == 10) ? 1 : 0); // 16.1ms between frames if reading data */
if (--adj <= 0) adj = 10;
} else {
poll_timer += 13 + ((adj == 3) ? 1 : 0); // 13.33ms otherwise (including latency counts) */
if (adj > 3) adj = 3;
if (--adj <= 0) adj = 3;
}
if (pcecdd.has_status && !pcecdd.latency) {
uint16_t s;

8
support/pcecd/pcecdd.cpp
View File

@@ -538,7 +538,13 @@ void pcecdd_t::CommandExec() {
new_lba = this->toc.tracks[index].start;
}*/
this->latency = (int)(get_cd_seek_ms(this->lba, new_lba)/13.33);
/* HuVideo streams by fetching 120 sectors at a time, taking advantage of the geometry
* of the disc to reduce/eliminate seek time */
if ((this->lba == new_lba) && (cnt_ == 120)) {
this->latency = 0;
} else {
this->latency = (int)(get_cd_seek_ms(this->lba, new_lba)/13.33);
}
printf("seek time ticks: %d\n", this->latency);
this->lba = new_lba;

12
support/pcecd/seektime.cpp
View File

@@ -93,27 +93,27 @@ float get_cd_seek_ms(int start_sector, int target_sector)
// Now, we use the algorithm to determine how long to wait
if (abs(target_sector - start_sector) < 2)
{
milliseconds = (3 * 1000 / 60);
milliseconds = (2 * 1000 / 60);
}
else if (abs(target_sector - start_sector) < 5)
{
milliseconds = (9 * 1000 / 60) + (float)(sector_list[target_index].rotation_ms * 0.7);
milliseconds = (9 * 1000 / 60) + (float)(sector_list[target_index].rotation_ms * 0.75);
}
else if (track_difference <= 80)
{
milliseconds = (16 * 1000 / 60) + (float)(sector_list[target_index].rotation_ms * 0.7);
milliseconds = (17 * 1000 / 60) + (float)(sector_list[target_index].rotation_ms * 0.75);
}
else if (track_difference <= 160)
{
milliseconds = (22 * 1000 / 60) + (float)(sector_list[target_index].rotation_ms * 0.7);
milliseconds = (22 * 1000 / 60) + (float)(sector_list[target_index].rotation_ms * 0.75);
}
else if (track_difference <= 644)
{
milliseconds = (22 * 1000 / 60) + (float)(sector_list[target_index].rotation_ms * 0.7) + (float)((track_difference - 161) * 16.66 / 80);
milliseconds = (22 * 1000 / 60) + (float)(sector_list[target_index].rotation_ms * 0.75) + (float)((track_difference - 161) * 16.66 / 80);
}
else
{
milliseconds = (36 * 1000 / 60) + (float)((track_difference - 644) * 16.66 / 195);
milliseconds = (36 * 1000 / 60) + (float)(sector_list[target_index].rotation_ms * 0.5) + (float)((track_difference - 644) * 16.66 / 195);
}
printf("From sector %d to sector %d:\n", start_sector, target_sector);