[FFmpeg-devel] [PATCH] avformat: add Scenarist Closed Captions demuxer
Paul B Mahol
onemda at gmail.com
Tue Jan 24 19:43:31 EET 2017
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/sccdec.c | 166 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 168 insertions(+)
create mode 100644 libavformat/sccdec.c
diff --git a/libavformat/Makefile b/libavformat/Makefile
index f30bc94..a458402 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -434,6 +434,7 @@ OBJS-$(CONFIG_SAMI_DEMUXER) += samidec.o subtitles.o
OBJS-$(CONFIG_SAP_DEMUXER) += sapdec.o
OBJS-$(CONFIG_SAP_MUXER) += sapenc.o
OBJS-$(CONFIG_SBG_DEMUXER) += sbgdec.o
+OBJS-$(CONFIG_SCC_DEMUXER) += sccdec.o subtitles.o
OBJS-$(CONFIG_SDP_DEMUXER) += rtsp.o
OBJS-$(CONFIG_SDR2_DEMUXER) += sdr2.o
OBJS-$(CONFIG_SDS_DEMUXER) += sdsdec.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index e30305b..45140f4 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -273,6 +273,7 @@ void av_register_all(void)
REGISTER_DEMUXER (SAMI, sami);
REGISTER_MUXDEMUX(SAP, sap);
REGISTER_DEMUXER (SBG, sbg);
+ REGISTER_DEMUXER (SCC, scc);
REGISTER_DEMUXER (SDP, sdp);
REGISTER_DEMUXER (SDR2, sdr2);
REGISTER_DEMUXER (SDS, sds);
diff --git a/libavformat/sccdec.c b/libavformat/sccdec.c
new file mode 100644
index 0000000..4d22908
--- /dev/null
+++ b/libavformat/sccdec.c
@@ -0,0 +1,166 @@
+/*
+ * SCC subtitle demuxer
+ * Copyright (c) 2017 Paul B Mahol
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "avformat.h"
+#include "internal.h"
+#include "subtitles.h"
+#include "libavutil/bprint.h"
+#include "libavutil/intreadwrite.h"
+
+typedef struct SCCContext {
+ FFDemuxSubtitlesQueue q;
+} SCCContext;
+
+static int scc_probe(AVProbeData *p)
+{
+ char buf[128];
+ FFTextReader tr;
+
+ ff_text_init_buf(&tr, p->buf, p->buf_size);
+
+ while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
+ ff_text_r8(&tr);
+
+ if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0)
+ return 0;
+
+ if (!memcmp(buf, "Scenarist_SCC V1.0", 18))
+ return AVPROBE_SCORE_MAX;
+
+ return 0;
+}
+
+static int convert(uint8_t x)
+{
+ if (x >= 'a')
+ x -= 87;
+ else if (x >= 'A')
+ x -= 55;
+ else
+ x -= '0';
+ return x;
+}
+
+static int scc_read_header(AVFormatContext *s)
+{
+ SCCContext *scc = s->priv_data;
+ AVStream *st = avformat_new_stream(s, NULL);
+ char line[4096];
+ uint8_t out[4096];
+ FFTextReader tr;
+ int ret = 0;
+
+ ff_text_init_avio(s, &tr, s->pb);
+
+ if (!st)
+ return AVERROR(ENOMEM);
+ avpriv_set_pts_info(st, 64, 1, 1000);
+ st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
+ st->codecpar->codec_id = AV_CODEC_ID_EIA_608;
+
+ while (!ff_text_eof(&tr)) {
+ const int64_t pos = ff_text_pos(&tr);
+ ptrdiff_t len = ff_subtitles_read_line(&tr, line, sizeof(line));
+ char *saveptr = NULL, *lline = (char *)&line;
+ int hh1, mm1, ss1, fs1, i;
+ int64_t ts_start;
+ AVPacket *sub;
+
+ if (len < 0)
+ break;
+
+ if (!len || !line[0])
+ continue;
+
+ if (!strncmp(line, "Scenarist_SCC V1.0", 18))
+ continue;
+
+ if (len < 12 || sscanf(line, "%d:%d:%d:%d", &hh1, &mm1, &ss1, &fs1) != 4)
+ continue;
+ ts_start = (hh1 * 3600LL + mm1 * 60LL + ss1) * 1000LL + fs1 * 33;
+
+ lline += 12;
+
+ for (i = 0; i < 4095; i += 3) {
+ char *ptr = av_strtok(lline, " ", &saveptr);
+ char c1, c2, c3, c4;
+
+ if (!ptr)
+ break;
+
+ if (sscanf(ptr, "%c%c%c%c", &c1, &c2, &c3, &c4) != 4)
+ break;
+
+ lline = NULL;
+ out[i+0] = 0xfc;
+ out[i+1] = convert(c2) | (convert(c1) << 4);
+ out[i+2] = convert(c4) | (convert(c3) << 4);
+ }
+ out[i] = 0;
+
+ sub = ff_subtitles_queue_insert(&scc->q, out, i, 0);
+ if (!sub) {
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+ sub->pos = pos;
+ sub->pts = ts_start;
+ sub->duration = 1500;
+ }
+
+ ff_subtitles_queue_finalize(s, &scc->q);
+
+end:
+ return ret;
+}
+
+static int scc_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ SCCContext *scc = s->priv_data;
+ return ff_subtitles_queue_read_packet(&scc->q, pkt);
+}
+
+static int scc_read_seek(AVFormatContext *s, int stream_index,
+ int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
+{
+ SCCContext *scc = s->priv_data;
+ return ff_subtitles_queue_seek(&scc->q, s, stream_index,
+ min_ts, ts, max_ts, flags);
+}
+
+static int scc_read_close(AVFormatContext *s)
+{
+ SCCContext *scc = s->priv_data;
+ ff_subtitles_queue_clean(&scc->q);
+ return 0;
+}
+
+AVInputFormat ff_scc_demuxer = {
+ .name = "scc",
+ .long_name = NULL_IF_CONFIG_SMALL("Scenarist Closed Captions"),
+ .priv_data_size = sizeof(SCCContext),
+ .read_probe = scc_probe,
+ .read_header = scc_read_header,
+ .read_packet = scc_read_packet,
+ .read_seek2 = scc_read_seek,
+ .read_close = scc_read_close,
+ .extensions = "scc",
+};
--
2.9.3
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