path: root/libavformat/sccenc.c (plain)
blob: f3cf3d599cc15a7da99a6776a8e4a0567d4d1572

1	/*
2	* SCC muxer
3	* Copyright (c) 2017 Paul B Mahol
4	*
5	* This file is part of FFmpeg.
6	*
7	* FFmpeg is free software; you can redistribute it and/or
8	* modify it under the terms of the GNU Lesser General Public
9	* License as published by the Free Software Foundation; either
10	* version 2.1 of the License, or (at your option) any later version.
11	*
12	* FFmpeg is distributed in the hope that it will be useful,
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15	* Lesser General Public License for more details.
16	*
17	* You should have received a copy of the GNU Lesser General Public
18	* License along with FFmpeg; if not, write to the Free Software
19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	*/
21
22	#include "avformat.h"
23	#include "internal.h"
24	#include "libavutil/log.h"
25	#include "libavutil/intreadwrite.h"
26
27	typedef struct SCCContext {
28	int prev_h, prev_m, prev_s, prev_f;
29	int inside;
30	int n;
31	} SCCContext;
32
33	static int scc_write_header(AVFormatContext *avf)
34	{
35	SCCContext *scc = avf->priv_data;
36
37	if (avf->nb_streams != 1 ||
38	avf->streams[0]->codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
39	av_log(avf, AV_LOG_ERROR,
40	"SCC supports only a single subtitles stream.\n");
41	return AVERROR(EINVAL);
42	}
43	if (avf->streams[0]->codecpar->codec_id != AV_CODEC_ID_EIA_608) {
44	av_log(avf, AV_LOG_ERROR,
45	"Unsupported subtitles codec: %s\n",
46	avcodec_get_name(avf->streams[0]->codecpar->codec_id));
47	return AVERROR(EINVAL);
48	}
49	avpriv_set_pts_info(avf->streams[0], 64, 1, 1000);
50	avio_printf(avf->pb, "Scenarist_SCC V1.0\n");
51
52	scc->prev_h = scc->prev_m = scc->prev_s = scc->prev_f = -1;
53	scc->inside = 0;
54
55	return 0;
56	}
57
58	static int scc_write_packet(AVFormatContext *avf, AVPacket *pkt)
59	{
60	SCCContext *scc = avf->priv_data;
61	int64_t pts = pkt->pts;
62	int i, h, m, s, f;
63
64	if (pts == AV_NOPTS_VALUE) {
65	av_log(avf, AV_LOG_WARNING,
66	"Insufficient timestamps.\n");
67	return 0;
68	}
69
70	h = (int)(pts / (3600000));
71	m = (int)(pts / (60000)) % 60;
72	s = (int)(pts / 1000) % 60;
73	f = (int)(pts % 1000) / 33;
74
75	for (i = 0; i < pkt->size; i+=3) {
76	if (pkt->data[i] == 0xfc && ((pkt->data[i + 1] != 0x80 || pkt->data[i + 2] != 0x80)))
77	break;
78	}
79	if (i >= pkt->size)
80	return 0;
81
82	if (!scc->inside && (scc->prev_h != h || scc->prev_m != m || scc->prev_s != s || scc->prev_f != f)) {
83	avio_printf(avf->pb, "\n%02d:%02d:%02d:%02d\t", h, m, s, f);
84	scc->inside = 1;
85	}
86	for (i = 0; i < pkt->size; i+=3) {
87	if (i + 3 > pkt->size)
88	break;
89
90	if (pkt->data[i] != 0xfc || (pkt->data[i + 1] == 0x80 && pkt->data[i + 2] == 0x80))
91	continue;
92	if (!scc->inside) {
93	avio_printf(avf->pb, "\n%02d:%02d:%02d:%02d\t", h, m, s, f);
94	scc->inside = 1;
95	}
96	if (scc->n > 0)
97	avio_printf(avf->pb, " ");
98	avio_printf(avf->pb, "%02x%02x", pkt->data[i + 1], pkt->data[i + 2]);
99	scc->n++;
100	}
101	if (scc->inside && (scc->prev_h != h || scc->prev_m != m || scc->prev_s != s || scc->prev_f != f)) {
102	avio_printf(avf->pb, "\n");
103	scc->n = 0;
104	scc->inside = 0;
105	}
106
107	scc->prev_h = h;
108	scc->prev_m = m;
109	scc->prev_s = s;
110	scc->prev_f = f;
111	return 0;
112	}
113
114	AVOutputFormat ff_scc_muxer = {
115	.name = "scc",
116	.long_name = NULL_IF_CONFIG_SMALL("Scenarist Closed Captions"),
117	.extensions = "scc",
118	.priv_data_size = sizeof(SCCContext),
119	.write_header = scc_write_header,
120	.write_packet = scc_write_packet,
121	.flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
122	.subtitle_codec = AV_CODEC_ID_EIA_608,
123	};
124