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mpv/video/out/present_sync.c

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vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
/*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <time.h>
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
#include "misc/linked_list.h"
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
#include "mpv_talloc.h"
#include "osdep/timer.h"
#include "present_sync.h"
/* General nonsense about this mechanism.
*
* This requires that that caller has access to two, related values:
* (ust, msc): clock time and incrementing counter of last vsync (this is
* increased continuously, even if we don't swap)
*
various: remove trailing whitespace
2023-10-29 17:41:26 +00:00
* Note that this concept originates from the GLX_OML_sync_control extension
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
* which includes another parameter: sbc (swap counter of frame that was
* last displayed). Both the xorg present extension and wayland's
* presentation-time protocol do not include sbc values so they are omitted
* from this mechanism. mpv does not need to keep track of sbc calls and can
* have reliable presentation without it.
*/
void present_sync_get_info(struct mp_present *present, struct vo_vsync_info *info)
{
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
struct mp_present_entry *cur = present->head;
while (cur) {
if (cur->queue_display_time)
break;
cur = cur->list_node.next;
}
if (!cur)
return;
info->vsync_duration = cur->vsync_duration;
info->skipped_vsyncs = cur->skipped_vsyncs;
info->last_queue_display_time = cur->queue_display_time;
// Remove from the list, zero out everything, and append at the end
LL_REMOVE(list_node, present, cur);
*cur = (struct mp_present_entry){0};
LL_APPEND(list_node, present, cur);
}
present_sync: only save as many entries as the swapchain depth Saving more than the swapchain depth is just wasteful. We can just save a copy of the vo_opts here and check the value whenever we're updating values.
2023-11-06 22:35:04 +00:00
struct mp_present *mp_present_initialize(void *talloc_ctx, struct mp_vo_opts *opts, int entries)
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
{
struct mp_present *present = talloc_zero(talloc_ctx, struct mp_present);
for (int i = 0; i < entries; i++) {
struct mp_present_entry *entry = talloc_zero(present, struct mp_present_entry);
LL_APPEND(list_node, present, entry);
}
present_sync: only save as many entries as the swapchain depth Saving more than the swapchain depth is just wasteful. We can just save a copy of the vo_opts here and check the value whenever we're updating values.
2023-11-06 22:35:04 +00:00
present->opts = opts;
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
return present;
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
}
void present_sync_swap(struct mp_present *present)
{
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
struct mp_present_entry *cur = present->head;
while (cur) {
if (!cur->queue_display_time)
break;
cur = cur->list_node.next;
}
if (!cur)
return;
int64_t ust = cur->ust;
int64_t msc = cur->msc;
int64_t last_ust = cur->list_node.prev ? cur->list_node.prev->ust : 0;
int64_t last_msc = cur->list_node.prev ? cur->list_node.prev->msc : 0;
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
// Avoid attempting to use any presentation statistics if the ust is 0 or has
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
// not actually updated (i.e. the last_ust is equal to ust).
if (!ust || ust == last_ust) {
cur->skipped_vsyncs = -1;
cur->vsync_duration = -1;
cur->queue_display_time = -1;
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
return;
}
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
cur->skipped_vsyncs = 0;
int64_t ust_passed = ust ? ust - last_ust: 0;
int64_t msc_passed = msc ? msc - last_msc: 0;
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
if (msc_passed && ust_passed)
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
cur->vsync_duration = ust_passed / msc_passed;
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
struct timespec ts;
present_sync: allow future timestamps The original OML sync implementation (which is where this calculation originally comes from) made now_monotonic and ust_mp_time unsigned. This is fine except it has the assumption that now_monotonic is always greater than ust. This actually isn't always the case. In wayland, I observed instances where the reported timestamp is in the future. Of course, it's a valid question to wonder if this even makes sense but these UST values are essentially opaque black boxes to us anyways. It's entirely plausible that the gpu is expecting the actual presentation of the last swap to be a bit in the future, the compositor gets this and reports this to us. So we'll consider such stats as valid. Note that xorg doesn't have this problem because it's roughly one swap buffer call behind because of how the event loop works (honestly something that should be fixed). Of course, the problem with the unsigned type here is that it overflows on the subtraction so make it signed and allow the appropriate negative value to happen if it does. Note that this will simply result in a small addition to mp_time_us() which is exactly what we want here (timestamp slightly in the future). Some small style changes included just because.
2023-09-13 03:17:05 +00:00
if (clock_gettime(CLOCK_MONOTONIC, &ts))
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
return;
timer: use MP_TIME macros
2023-10-22 02:31:36 +00:00
int64_t now_monotonic = MP_TIME_S_TO_NS(ts.tv_sec) + ts.tv_nsec;
vo: change vsync base to nanoseconds There is no reason to use microseconds precision. We have precise timers all all relevant platforms.
2023-09-16 02:45:24 +00:00
int64_t ust_mp_time = mp_time_ns() - (now_monotonic - ust);
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
cur->queue_display_time = ust_mp_time;
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
}
present_sync: rename function to present_sync_update_values This had to have been a mistake. It was just confusing.
2023-11-02 21:03:03 +00:00
void present_sync_update_values(struct mp_present *present, int64_t ust,
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
int64_t msc)
{
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
struct mp_present_entry *cur = present->head;
present_sync: only save as many entries as the swapchain depth Saving more than the swapchain depth is just wasteful. We can just save a copy of the vo_opts here and check the value whenever we're updating values.
2023-11-06 22:35:04 +00:00
int index = 0;
while (cur && ++index) {
if (!cur->ust || index == present->opts->swapchain_depth)
present_sync: rewrite around linked list When this was originally written, the queuing/list approach was deliberately removed since it adds more complication and xorg/wayland don't really use it anyway. In practice, you only really have one frame in flight with presentation timestamps. However, one slight annoyance is that the drm code has its own thing which is almost exactly the same and does its own calculations. Ideally, we'd port drm to this instead, but the implementation there takes into account N-frames in flight which probably does actually work. So we need to make present_sync smarter and be able to handle this. mpv does actually have its own linked list implementation already which is a good fit for this. mp_present becomes the list and each mp_present_entry has its own set of timestamps. During initialization, we create all the entries we need and then simply treat it like a queue during the lifecycle of the VO. When an entry is fully used (present_sync_get_info), then we remove it from the list, zero it out, and append it to the end for future use. This avoids needing to allocate memory on every frame (which is what drm currently does) and allows for a reasonable number of in flight frames at the same time as this should never grow to some obscene number. The nice thing is that current users of present_sync don't need to change anything besides the initialization step.
2023-11-02 18:41:32 +00:00
break;
cur = cur->list_node.next;
}
if (!cur)
return;
cur->ust = ust;
cur->msc = msc;
vo: move wayland presentation to separate files Wayland had some specific code that it used for implementing the presentation time protocol. It turns out that xorg's present extension is extremely similar, so it would be silly to duplicate this whole mess again. Factor this out to separate, independent code and introduce the mp_present struct which is used for handling the ust/msc values and some other associated values. Also, add in some helper functions so all the dirty details live specifically in present_sync. The only wayland-specific part is actually obtaining ust/msc values. Since only wayland or xorg are expected to use this, add a conditional to the build that only adds this file when either one of those are present. You may observe that sbc is completely omitted. This field existed in wayland, but was completely unused (presentation time doesn't return this). Xorg's present extension also doesn't use this so just get rid of it all together. The actual calculation is slightly altered so it is correct for our purposes. We want to get the presentation event of the last frame that was just occured (this function executes right after the buffer swap). The adjustment is to just remove the vsync_duration subtraction. Also, The overly-complicated queue approach is removed. This has no actual use in practice (on wayland or xorg). Presentation statistics are only ever used after the immediate preceding swap to update vsync timings or thrown away.
2022-06-10 16:49:28 +00:00
}