mirror of
https://github.com/mpv-player/mpv
synced 2024-12-23 23:32:26 +00:00
95 lines
2.8 KiB
C
95 lines
2.8 KiB
C
/*
|
|
* This file is part of mpv.
|
|
*
|
|
* SRT timestamp parsing code lifted from FFmpeg srtdec.c (LGPL).
|
|
*
|
|
* 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 <inttypes.h>
|
|
#include <assert.h>
|
|
|
|
#include "bstr/bstr.h"
|
|
#include "sd.h"
|
|
|
|
/*
|
|
* Background:
|
|
*
|
|
* Libav's .srt demuxer outputs packets that contain parts of the subtitle
|
|
* event header. Also, the packet duration is not set (they don't parse it
|
|
* on the demuxer side). As a result, the srt demuxer is useless.
|
|
*
|
|
* However, we can fix it by parsing the header, which spares us from writing
|
|
* a full SRT demuxer.
|
|
*
|
|
* Newer versions of FFmpeg do not have this problem. To avoid compatibility
|
|
* problems, they changed the codec name from "srt" to "subrip".
|
|
*
|
|
* Summary: this is a hack for broken SRT stuff in Libav.
|
|
*
|
|
*/
|
|
|
|
static bool supports_format(const char *format)
|
|
{
|
|
return format && strcmp(format, "srt") == 0;
|
|
}
|
|
|
|
static int init(struct sd *sd)
|
|
{
|
|
sd->output_codec = "subrip";
|
|
return 0;
|
|
}
|
|
|
|
static bool parse_pts(bstr header, double *duration)
|
|
{
|
|
char buf[200];
|
|
snprintf(buf, sizeof(buf), "%.*s", BSTR_P(header));
|
|
int hh1, mm1, ss1, ms1;
|
|
int hh2, mm2, ss2, ms2;
|
|
if (sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d",
|
|
&hh1, &mm1, &ss1, &ms1, &hh2, &mm2, &ss2, &ms2) >= 8)
|
|
{
|
|
int64_t start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1;
|
|
int64_t end = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2;
|
|
*duration = (end - start) / 1000.0;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static void decode(struct sd *sd, struct demux_packet *packet)
|
|
{
|
|
bstr data = {packet->buffer, packet->len};
|
|
// Remove the broken header. It's usually on the second or first line.
|
|
bstr left = data;
|
|
while (left.len) {
|
|
bstr line = bstr_getline(left, &left);
|
|
if (parse_pts(line, &packet->duration)) {
|
|
data = left;
|
|
break;
|
|
}
|
|
}
|
|
sd_conv_add_packet(sd, data.start, data.len, packet->pts, packet->duration);
|
|
}
|
|
|
|
const struct sd_functions sd_lavf_srt = {
|
|
.name = "lavf_srt",
|
|
.supports_format = supports_format,
|
|
.init = init,
|
|
.decode = decode,
|
|
.get_converted = sd_conv_def_get_converted,
|
|
.reset = sd_conv_def_reset,
|
|
};
|