mpv/sub/sd_lavc.c

479 lines
14 KiB
C

/*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <assert.h>
#include <math.h>
#include <libavcodec/avcodec.h>
#include <libavutil/common.h>
#include <libavutil/intreadwrite.h>
#include "config.h"
#include "talloc.h"
#include "common/msg.h"
#include "common/av_common.h"
#include "demux/stheader.h"
#include "options/options.h"
#include "video/mp_image.h"
#include "sd.h"
#include "dec_sub.h"
#define MAX_QUEUE 4
struct sub {
bool valid;
AVSubtitle avsub;
int count;
struct sub_bitmap *inbitmaps;
struct osd_bmp_indexed *imgs;
double pts;
double endpts;
int64_t id;
};
struct seekpoint {
double pts;
double endpts;
};
struct sd_lavc_priv {
AVCodecContext *avctx;
struct sub subs[MAX_QUEUE]; // most recent event first
struct sub_bitmap *outbitmaps;
int64_t displayed_id;
int64_t new_id;
struct mp_image_params video_params;
double current_pts;
struct seekpoint *seekpoints;
int num_seekpoints;
};
static bool supports_format(const char *format)
{
enum AVCodecID cid = mp_codec_to_av_codec_id(format);
// Supported codecs must be known to decode to paletted bitmaps
switch (cid) {
case AV_CODEC_ID_DVB_SUBTITLE:
case AV_CODEC_ID_HDMV_PGS_SUBTITLE:
case AV_CODEC_ID_XSUB:
case AV_CODEC_ID_DVD_SUBTITLE:
return true;
default:
return false;
}
}
static void get_resolution(struct sd *sd, int wh[2])
{
struct sd_lavc_priv *priv = sd->priv;
enum AVCodecID codec = priv->avctx->codec_id;
int *w = &wh[0], *h = &wh[1];
*w = priv->avctx->width;
*h = priv->avctx->height;
if (codec == AV_CODEC_ID_DVD_SUBTITLE) {
if (*w <= 0 || *h <= 0) {
*w = priv->video_params.w;
*h = priv->video_params.h;
}
/* XXX Although the video frame is some size, the SPU frame is
always maximum size i.e. 720 wide and 576 or 480 high */
// For HD files in MKV the VobSub resolution can be higher though,
// see largeres_vobsub.mkv
if (*w <= 720 && *h <= 576) {
*w = 720;
*h = (*h == 480 || *h == 240) ? 480 : 576;
}
} else {
// Hope that PGS subs set these and 720/576 works for dvb subs
if (!*w)
*w = 720;
if (!*h)
*h = 576;
}
}
static int init(struct sd *sd)
{
struct sd_lavc_priv *priv = talloc_zero(NULL, struct sd_lavc_priv);
enum AVCodecID cid = mp_codec_to_av_codec_id(sd->sh->codec);
AVCodecContext *ctx = NULL;
AVCodec *sub_codec = avcodec_find_decoder(cid);
if (!sub_codec)
goto error;
ctx = avcodec_alloc_context3(sub_codec);
if (!ctx)
goto error;
mp_lavc_set_extradata(ctx, sd->sh->extradata, sd->sh->extradata_size);
if (avcodec_open2(ctx, sub_codec, NULL) < 0)
goto error;
priv->avctx = ctx;
sd->priv = priv;
priv->displayed_id = -1;
priv->current_pts = MP_NOPTS_VALUE;
return 0;
error:
MP_FATAL(sd, "Could not open libavcodec subtitle decoder\n");
av_free(ctx);
talloc_free(priv);
return -1;
}
static void clear_sub(struct sub *sub)
{
sub->count = 0;
sub->pts = MP_NOPTS_VALUE;
sub->endpts = MP_NOPTS_VALUE;
if (sub->valid)
avsubtitle_free(&sub->avsub);
sub->valid = false;
}
static void alloc_sub(struct sd_lavc_priv *priv)
{
clear_sub(&priv->subs[MAX_QUEUE - 1]);
struct sub tmp = priv->subs[MAX_QUEUE - 1];
for (int n = MAX_QUEUE - 1; n > 0; n--)
priv->subs[n] = priv->subs[n - 1];
priv->subs[0] = tmp;
// clear only some fields; the memory allocs can be reused
priv->subs[0].valid = false;
priv->subs[0].count = 0;
priv->subs[0].id = priv->new_id++;
}
static void decode(struct sd *sd, struct demux_packet *packet)
{
struct MPOpts *opts = sd->opts;
struct sd_lavc_priv *priv = sd->priv;
AVCodecContext *ctx = priv->avctx;
double pts = packet->pts;
double endpts = MP_NOPTS_VALUE;
double duration = packet->duration;
AVSubtitle sub;
AVPacket pkt;
// libavformat sets duration==0, even if the duration is unknown.
// Assume there are no bitmap subs that actually use duration==0 for
// hidden subtitle events.
if (duration == 0)
duration = -1;
if (pts == MP_NOPTS_VALUE)
MP_WARN(sd, "Subtitle with unknown start time.\n");
av_init_packet(&pkt);
pkt.data = packet->buffer;
pkt.size = packet->len;
int got_sub;
int res = avcodec_decode_subtitle2(ctx, &sub, &got_sub, &pkt);
if (res < 0 || !got_sub)
return;
if (pts != MP_NOPTS_VALUE) {
if (sub.end_display_time > sub.start_display_time &&
sub.end_display_time != UINT32_MAX)
{
duration = (sub.end_display_time - sub.start_display_time) / 1000.0;
}
pts += sub.start_display_time / 1000.0;
if (duration >= 0)
endpts = pts + duration;
// set end time of previous sub
struct sub *prev = &priv->subs[0];
if (prev->valid) {
if (prev->endpts == MP_NOPTS_VALUE || prev->endpts > pts)
prev->endpts = pts;
if (opts->sub_fix_timing && pts - prev->endpts <= SUB_GAP_THRESHOLD)
prev->endpts = pts;
for (int n = 0; n < priv->num_seekpoints; n++) {
if (priv->seekpoints[n].pts == prev->pts) {
priv->seekpoints[n].endpts = prev->endpts;
break;
}
}
}
// This subtitle packet only signals the end of subtitle display.
if (!sub.num_rects) {
avsubtitle_free(&sub);
return;
}
}
alloc_sub(priv);
struct sub *current = &priv->subs[0];
current->valid = true;
current->pts = pts;
current->endpts = endpts;
current->avsub = sub;
MP_TARRAY_GROW(priv, current->inbitmaps, sub.num_rects);
MP_TARRAY_GROW(priv, current->imgs, sub.num_rects);
for (int i = 0; i < sub.num_rects; i++) {
struct AVSubtitleRect *r = sub.rects[i];
struct sub_bitmap *b = &current->inbitmaps[current->count];
struct osd_bmp_indexed *img = &current->imgs[current->count];
if (r->type != SUBTITLE_BITMAP) {
MP_ERR(sd, "unsupported subtitle type from libavcodec\n");
continue;
}
if (!(r->flags & AV_SUBTITLE_FLAG_FORCED) && opts->forced_subs_only)
continue;
if (r->w <= 0 || r->h <= 0)
continue;
#if HAVE_AV_SUBTITLE_NOPICT
uint8_t **data = r->data;
int *linesize = r->linesize;
#else
uint8_t **data = r->pict.data;
int *linesize = r->pict.linesize;
#endif
img->bitmap = data[0];
assert(r->nb_colors > 0);
assert(r->nb_colors * 4 <= sizeof(img->palette));
memcpy(img->palette, data[1], r->nb_colors * 4);
b->bitmap = img;
b->stride = linesize[0];
b->w = r->w;
b->h = r->h;
b->x = r->x;
b->y = r->y;
current->count++;
}
if (pts != MP_NOPTS_VALUE) {
for (int n = 0; n < priv->num_seekpoints; n++) {
if (priv->seekpoints[n].pts == pts)
goto skip;
}
// Set arbitrary limit as safe-guard against insane files.
if (priv->num_seekpoints >= 10000)
MP_TARRAY_REMOVE_AT(priv->seekpoints, priv->num_seekpoints, 0);
MP_TARRAY_APPEND(priv, priv->seekpoints, priv->num_seekpoints,
(struct seekpoint){.pts = pts, .endpts = endpts});
skip: ;
}
}
static void get_bitmaps(struct sd *sd, struct mp_osd_res d, double pts,
struct sub_bitmaps *res)
{
struct sd_lavc_priv *priv = sd->priv;
struct MPOpts *opts = sd->opts;
priv->current_pts = pts;
struct sub *current = NULL;
for (int n = MAX_QUEUE - 1; n >= 0; n--) {
struct sub *sub = &priv->subs[n];
if (!sub->valid)
continue;
if (pts == MP_NOPTS_VALUE ||
((sub->pts == MP_NOPTS_VALUE || pts >= sub->pts) &&
(sub->endpts == MP_NOPTS_VALUE || pts < sub->endpts)))
{
// Ignore "trailing" subtitles with unknown length after 1 minute.
if (sub->endpts == MP_NOPTS_VALUE && pts >= sub->pts + 60)
break;
current = sub;
break;
}
}
if (!current)
return;
MP_TARRAY_GROW(priv, priv->outbitmaps, current->count);
for (int n = 0; n < current->count; n++)
priv->outbitmaps[n] = current->inbitmaps[n];
res->parts = priv->outbitmaps;
res->num_parts = current->count;
if (priv->displayed_id != current->id)
res->change_id++;
priv->displayed_id = current->id;
res->format = SUBBITMAP_INDEXED;
double video_par = 0;
if (priv->avctx->codec_id == AV_CODEC_ID_DVD_SUBTITLE &&
opts->stretch_dvd_subs)
{
// For DVD subs, try to keep the subtitle PAR at display PAR.
double par = priv->video_params.p_w / (double)priv->video_params.p_h;
if (isnormal(par))
video_par = par;
}
if (priv->avctx->codec_id == AV_CODEC_ID_HDMV_PGS_SUBTITLE)
video_par = -1;
if (opts->stretch_image_subs)
d.ml = d.mr = d.mt = d.mb = 0;
int insize[2];
get_resolution(sd, insize);
for (int n = 0; n < res->num_parts; n++) {
struct sub_bitmap *p = &res->parts[n];
if ((p->x + p->w > insize[0] || p->y + p->h > insize[1]) &&
priv->video_params.w > insize[0] && priv->video_params.h > insize[1])
{
insize[0] = priv->video_params.w;
insize[1] = priv->video_params.h;
}
}
osd_rescale_bitmaps(res, insize[0], insize[1], d, video_par);
}
static bool accepts_packet(struct sd *sd)
{
struct sd_lavc_priv *priv = sd->priv;
double pts = priv->current_pts;
int last_needed = -1;
for (int n = 0; n < MAX_QUEUE; n++) {
struct sub *sub = &priv->subs[n];
if (!sub->valid)
continue;
if (pts == MP_NOPTS_VALUE ||
((sub->pts == MP_NOPTS_VALUE || sub->pts >= pts) ||
(sub->endpts == MP_NOPTS_VALUE || pts < sub->endpts)))
{
last_needed = n;
}
}
// We can accept a packet if it wouldn't overflow the fixed subtitle queue.
// We assume that get_bitmaps() never decreases the PTS.
return last_needed + 1 < MAX_QUEUE;
}
static void reset(struct sd *sd)
{
struct sd_lavc_priv *priv = sd->priv;
for (int n = 0; n < MAX_QUEUE; n++)
clear_sub(&priv->subs[n]);
// lavc might not do this right for all codecs; may need close+reopen
avcodec_flush_buffers(priv->avctx);
priv->current_pts = MP_NOPTS_VALUE;
}
static void uninit(struct sd *sd)
{
struct sd_lavc_priv *priv = sd->priv;
for (int n = 0; n < MAX_QUEUE; n++)
clear_sub(&priv->subs[n]);
avcodec_close(priv->avctx);
av_free(priv->avctx->extradata);
av_free(priv->avctx);
talloc_free(priv);
}
static int compare_seekpoint(const void *pa, const void *pb)
{
const struct seekpoint *a = pa, *b = pb;
return a->pts == b->pts ? 0 : (a->pts < b->pts ? -1 : +1);
}
// taken from ass_step_sub(), libass (ISC)
static double step_sub(struct sd *sd, double now, int movement)
{
struct sd_lavc_priv *priv = sd->priv;
int best = -1;
double target = now;
int direction = movement > 0 ? 1 : -1;
if (movement == 0 || priv->num_seekpoints == 0)
return MP_NOPTS_VALUE;
qsort(priv->seekpoints, priv->num_seekpoints, sizeof(priv->seekpoints[0]),
compare_seekpoint);
while (movement) {
int closest = -1;
double closest_time = 0;
for (int i = 0; i < priv->num_seekpoints; i++) {
struct seekpoint *p = &priv->seekpoints[i];
double start = p->pts;
if (direction < 0) {
double end = p->endpts == MP_NOPTS_VALUE ? INFINITY : p->endpts;
if (end < target) {
if (closest < 0 || end > closest_time) {
closest = i;
closest_time = end;
}
}
} else {
if (start > target) {
if (closest < 0 || start < closest_time) {
closest = i;
closest_time = start;
}
}
}
}
if (closest < 0)
break;
target = closest_time + direction;
best = closest;
movement -= direction;
}
return best < 0 ? 0 : priv->seekpoints[best].pts - now;
}
static int control(struct sd *sd, enum sd_ctrl cmd, void *arg)
{
struct sd_lavc_priv *priv = sd->priv;
switch (cmd) {
case SD_CTRL_SUB_STEP: {
double *a = arg;
double res = step_sub(sd, a[0], a[1]);
if (res == MP_NOPTS_VALUE)
return false;
a[0] = res;
return true;
}
case SD_CTRL_SET_VIDEO_PARAMS:
priv->video_params = *(struct mp_image_params *)arg;
return CONTROL_OK;
case SD_CTRL_GET_RESOLUTION:
get_resolution(sd, arg);
return CONTROL_OK;
default:
return CONTROL_UNKNOWN;
}
}
const struct sd_functions sd_lavc = {
.name = "lavc",
.supports_format = supports_format,
.init = init,
.decode = decode,
.get_bitmaps = get_bitmaps,
.accepts_packet = accepts_packet,
.control = control,
.reset = reset,
.uninit = uninit,
};