mpv/sub/dec_sub.h

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subs: libass: use a single persistent renderer for subtitles To draw libass subtitles, the code used ASS_Renderer objects created in vf_vo (VO rendering) or vf_ass. They were destroyed and recreated together with the video filter chain. Change the code to use a single persistent renderer instance stored in the main osd_state struct. Because libass seems to misbehave if fonts are changed while a renderer exists (even if ass_set_fonts() is called on the renderer afterwards), the renderer is recreated after adding embedded fonts. The known benefits are simpler code and avoiding delays when switching between timeline parts from different files (libass fontconfig initialization, needed when creating a new renderer, can take a long time in some cases; switching between files rebuilds the video filter chain, and this required recreating the renderers). On the other hand, I'm not sure whether this could cause inefficient bitmap caching in libass; explicitly resetting the renderer in some cases could be beneficial. The new code does not keep the distinction of separate renderers for vsfilter munged aspect vs normal; this means that changing subtitle tracks can lose cache for the previous track. The new code always sets some libass parameters on each rendering call, which were previously only set if they had potentially changed. This should be harmless as libass itself has checks to see if the values differ from previous ones. Conflicts: command.c libmpcodecs/vf_ass.c libmpcodecs/vf_vo.c mplayer.c sub/ass_mp.c
2012-08-25 14:47:50 +00:00
#ifndef MPLAYER_DEC_SUB_H
#define MPLAYER_DEC_SUB_H
#include <stdbool.h>
#include <stdint.h>
#include "osd.h"
struct sh_stream;
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struct mpv_global;
struct demux_packet;
struct mp_recorder_sink;
struct dec_sub;
struct sd;
enum sd_ctrl {
SD_CTRL_SUB_STEP,
SD_CTRL_SET_VIDEO_PARAMS,
SD_CTRL_SET_TOP,
SD_CTRL_SET_VIDEO_DEF_FPS,
sub: make filter_sdh a "proper" filter, allow runtime changes Until now, filter_sdh was simply a function that was called by sd_ass directly (if enabled). I want to add another filter, so it's time to turn this into a somewhat more general subtitle filtering infrastructure. I pondered whether to reuse the audio/video filtering stuff - but better not. Also, since subtitles are horrible and tend to refuse proper abstraction, it's still messed into sd_ass, instead of working on the dec_sub.c level. Actually mpv used to have subtitle "filters" and even made subtitle converters part of it, but it was fairly horrible, so don't do that again. In addition, make runtime changes possible. Since this was supposed to be a quick hack, I just decided to put all subtitle filter options into a separate option group (=> simpler change notification), to manually push the change through the playloop (like it was sort of before for OSD options), and to recreate the sub filter chain completely in every change. Should be good enough. One strangeness is that due to prefetching and such, most subtitle packets (or those some time ahead) are actually done filtering when we change, so the user still needs to manually seek to actually refresh everything. And since subtitle data is usually cached in ASS_Track (for other terrible but user-friendly reasons), we also must clear the subtitle data, but of course only on seek, since otherwise all subtitles would just disappear. What a fucking mess, but such is life. We could trigger a "refresh seek" to make this more automatic, but I don't feel like it currently. This is slightly inefficient (lots of allocations and copying), but I decided that it doesn't matter. Could matter slightly for crazy ASS subtitles that render with thousands of events. Not very well tested. Still seems to work, but I didn't have many test cases.
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SD_CTRL_UPDATE_OPTS,
};
enum sd_text_type {
SD_TEXT_TYPE_PLAIN,
SD_TEXT_TYPE_ASS,
};
struct sd_times {
double start;
double end;
};
struct attachment_list {
struct demux_attachment *entries;
int num_entries;
};
struct dec_sub *sub_create(struct mpv_global *global, struct sh_stream *sh,
sub: align ytdl-hook secondary subs to the top 29e15e6248 prefixed youtube-dl's subs url with an edl prefix to not download them until they're selected, which is useful when there are many sub languages. But this prefix broke the alignment of secondary subs, which would overlap the primary subs instead of always being placed at the top. This can be tested with --sub-file='edl://!no_clip;!delay_open,media_type=sub;secondary_sub.srt' When a sub is added, sub.c:reinit_sub() is called. This calls in init_subdec() -> dec_sub.c:sub_create() -> init_decoder() -> sd_ass:init(). Then reinit_sub() calls sub_control(track->d_sub, SD_CTRL_SET_TOP, &(bool){!!order}) which sets sd_ass_priv.on_top = true for secondary subs. But for EDL subs the real sub is initialized again when in dec_sub.c:sub_read_packets() is_new_segment() returns true and update_segment() is called, or when sub_get_bitmaps() calls update_segment(). update_segment() then calls init_decoder(), which calls sd_ass:init(), so sd_ass_priv is reinitialized, and its on_top property is left false. This commit sets it to true again. For URLs that need to be downloaded it seems that the update_segment() call that reinitializes sd_ass_priv is always the one in sub_read_packets(), but with local subs sub_get_bitmaps() is usually called earlier (though there shouldn't be a reason to use the EDL URL for local subs), so I added the order parameter to sub_create(), rather than adding it to all of update_segment(), sub_read_packets() and sub_get_bitmaps(). Also removes the cast to bool in the other sub_control call, since sub/sd_ass.c:control already casts arg to bool when cmd is SD_CTRL_SET_TOP.
2021-08-10 20:11:53 +00:00
struct attachment_list *attachments, int order);
void sub_destroy(struct dec_sub *sub);
bool sub_can_preload(struct dec_sub *sub);
void sub_preload(struct dec_sub *sub);
bool sub_read_packets(struct dec_sub *sub, double video_pts);
video: make OSD/subtitle bitmaps refcounted (sort of) Making OSD/subtitle bitmaps refcounted was planend a longer time ago, e.g. the sub_bitmaps.packed field (which refcounts the subtitle bitmap data) was added in 2016. But nothing benefited much from it, because struct sub_bitmaps was usually stack allocated, and there was this weird callback stuff through osd_draw(). Make it possible to get actually refcounted subtitle bitmaps on the OSD API level. For this, we just copy all subtitle data other than the bitmaps with sub_bitmaps_copy(). At first, I had planned some fancy refcount shit, but when that was a big mess and hard to debug and just boiled to emulating malloc(), I made it a full allocation+copy. This affects mostly the parts array. With crazy ASS subtitles, this parts array can get pretty big (thousands of elements or more), in which case the extra alloc/copy could become performance relevant. But then again this is just pure bullshit, and I see no need to care. In practice, this extra work most likely gets drowned out by libass murdering a single core (while mpv is waiting for it) anyway. So fuck it. I just wanted this so draw_bmp.c requires only a single call to render everything. VOs also can benefit from this, because the weird callback shit isn't necessary anymore (simpler code), but I haven't done anything about it yet. In general I'd hope this will work towards simplifying the OSD layer, which is prerequisite for making actual further improvements. I haven't tested some cases such as the "overlay-add" command. Maybe it crashes now? Who knows, who cares. In addition, it might be worthwhile to reduce the code duplication between all the things that output subtitle bitmaps (with repacking, image allocation, etc.), but that's orthogonal.
2020-04-26 21:34:32 +00:00
struct sub_bitmaps *sub_get_bitmaps(struct dec_sub *sub, struct mp_osd_res dim,
int format, double pts);
char *sub_get_text(struct dec_sub *sub, double pts, enum sd_text_type type);
struct sd_times sub_get_times(struct dec_sub *sub, double pts);
void sub_reset(struct dec_sub *sub);
void sub_select(struct dec_sub *sub, bool selected);
void sub_set_recorder_sink(struct dec_sub *sub, struct mp_recorder_sink *sink);
Implement backwards playback See manpage additions. This is a huge hack. You can bet there are shit tons of bugs. It's literally forcing square pegs into round holes. Hopefully, the manpage wall of text makes it clear enough that the whole shit can easily crash and burn. (Although it shouldn't literally crash. That would be a bug. It possibly _could_ start a fire by entering some sort of endless loop, not a literal one, just something where it tries to do work without making progress.) (Some obvious bugs I simply ignored for this initial version, but there's a number of potential bugs I can't even imagine. Normal playback should remain completely unaffected, though.) How this works is also described in the manpage. Basically, we demux in reverse, then we decode in reverse, then we render in reverse. The decoding part is the simplest: just reorder the decoder output. This weirdly integrates with the timeline/ordered chapter code, which also has special requirements on feeding the packets to the decoder in a non-straightforward way (it doesn't conflict, although a bugmessmass breaks correct slicing of segments, so EDL/ordered chapter playback is broken in backward direction). Backward demuxing is pretty involved. In theory, it could be much easier: simply iterating the usual demuxer output backward. But this just doesn't fit into our code, so there's a cthulhu nightmare of shit. To be specific, each stream (audio, video) is reversed separately. At least this means we can do backward playback within cached content (for example, you could play backwards in a live stream; on that note, it disables prefetching, which would lead to losing new live video, but this could be avoided). The fuckmess also meant that I didn't bother trying to support subtitles. Subtitles are a problem because they're "sparse" streams. They need to be "passively" demuxed: you don't try to read a subtitle packet, you demux audio and video, and then look whether there was a subtitle packet. This means to get subtitles for a time range, you need to know that you demuxed video and audio over this range, which becomes pretty messy when you demux audio and video backwards separately. Backward display is the most weird (and potentially buggy) part. To avoid that we need to touch a LOT of timing code, we negate all timestamps. The basic idea is that due to the navigation, all comparisons and subtractions of timestamps keep working, and you don't need to touch every single of them to "reverse" them. E.g.: bool before = pts_a < pts_b; would need to be: bool before = forward ? pts_a < pts_b : pts_a > pts_b; or: bool before = pts_a * dir < pts_b * dir; or if you, as it's implemented now, just do this after decoding: pts_a *= dir; pts_b *= dir; and then in the normal timing/renderer code: bool before = pts_a < pts_b; Consequently, we don't need many changes in the latter code. But some assumptions inhererently true for forward playback may have been broken anyway. What is mainly needed is fixing places where values are passed between positive and negative "domains". For example, seeking and timestamp user display always uses positive timestamps. The main mess is that it's not obvious which domain a given variable should or does use. Well, in my tests with a single file, it suddenly started to work when I did this. I'm honestly surprised that it did, and that I didn't have to change a single line in the timing code past decoder (just something minor to make external/cached text subtitles display). I committed it immediately while avoiding thinking about it. But there really likely are subtle problems of all sorts. As far as I'm aware, gstreamer also supports backward playback. When I looked at this years ago, I couldn't find a way to actually try this, and I didn't revisit it now. Back then I also read talk slides from the person who implemented it, and I'm not sure if and which ideas I might have taken from it. It's possible that the timestamp reversal is inspired by it, but I didn't check. (I think it claimed that it could avoid large changes by changing a sign?) VapourSynth has some sort of reverse function, which provides a backward view on a video. The function itself is trivial to implement, as VapourSynth aims to provide random access to video by frame numbers (so you just request decreasing frame numbers). From what I remember, it wasn't exactly fluid, but it worked. It's implemented by creating an index, and seeking to the target on demand, and a bunch of caching. mpv could use it, but it would either require using VapourSynth as demuxer and decoder for everything, or replacing the current file every time something is supposed to be played backwards. FFmpeg's libavfilter has reversal filters for audio and video. These require buffering the entire media data of the file, and don't really fit into mpv's architecture. It could be used by playing a libavfilter graph that also demuxes, but that's like VapourSynth but worse.
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void sub_set_play_dir(struct dec_sub *sub, int dir);
bool sub_is_secondary_visible(struct dec_sub *sub);
int sub_control(struct dec_sub *sub, enum sd_ctrl cmd, void *arg);
subs: libass: use a single persistent renderer for subtitles To draw libass subtitles, the code used ASS_Renderer objects created in vf_vo (VO rendering) or vf_ass. They were destroyed and recreated together with the video filter chain. Change the code to use a single persistent renderer instance stored in the main osd_state struct. Because libass seems to misbehave if fonts are changed while a renderer exists (even if ass_set_fonts() is called on the renderer afterwards), the renderer is recreated after adding embedded fonts. The known benefits are simpler code and avoiding delays when switching between timeline parts from different files (libass fontconfig initialization, needed when creating a new renderer, can take a long time in some cases; switching between files rebuilds the video filter chain, and this required recreating the renderers). On the other hand, I'm not sure whether this could cause inefficient bitmap caching in libass; explicitly resetting the renderer in some cases could be beneficial. The new code does not keep the distinction of separate renderers for vsfilter munged aspect vs normal; this means that changing subtitle tracks can lose cache for the previous track. The new code always sets some libass parameters on each rendering call, which were previously only set if they had potentially changed. This should be harmless as libass itself has checks to see if the values differ from previous ones. Conflicts: command.c libmpcodecs/vf_ass.c libmpcodecs/vf_vo.c mplayer.c sub/ass_mp.c
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#endif