[FFmpeg-cvslog] avcodec/libzvbi-teletextdec: add support for selecting subtitle pages only
Marton Balint
git at videolan.org
Mon Jun 11 00:57:43 EEST 2018
ffmpeg | branch: master | Marton Balint <cus at passwd.hu> | Sat Apr 28 21:42:34 2018 +0200| [d9f72e53bfe76b5c40bb444f0a81617dffdfedf4] | committer: Marton Balint
avcodec/libzvbi-teletextdec: add support for selecting subtitle pages only
Signed-off-by: Marton Balint <cus at passwd.hu>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d9f72e53bfe76b5c40bb444f0a81617dffdfedf4
---
doc/decoders.texi | 5 +++--
libavcodec/libzvbi-teletextdec.c | 33 +++++++++++++++++++++++----------
libavcodec/version.h | 2 +-
3 files changed, 27 insertions(+), 13 deletions(-)
diff --git a/doc/decoders.texi b/doc/decoders.texi
index a551d5d0fd..8f07bc1afb 100644
--- a/doc/decoders.texi
+++ b/doc/decoders.texi
@@ -248,8 +248,9 @@ configuration. You need to explicitly configure the build with
@table @option
@item txt_page
-List of teletext page numbers to decode. You may use the special * string to
-match all pages. Pages that do not match the specified list are dropped.
+List of teletext page numbers to decode. Pages that do not match the specified
+list are dropped. You may use the special @code{*} string to match all pages,
+or @code{subtitle} to match all subtitle pages.
Default value is *.
@item txt_chop_top
Discards the top teletext line. Default value is 1.
diff --git a/libavcodec/libzvbi-teletextdec.c b/libavcodec/libzvbi-teletextdec.c
index a800ad34ae..ccded23e7c 100644
--- a/libavcodec/libzvbi-teletextdec.c
+++ b/libavcodec/libzvbi-teletextdec.c
@@ -73,6 +73,7 @@ typedef struct TeletextContext
vbi_sliced sliced[MAX_SLICES];
int readorder;
+ uint8_t subtitle_map[2048];
} TeletextContext;
static int chop_spaces_utf8(const unsigned char* t, int len)
@@ -281,16 +282,14 @@ static void handler(vbi_event *ev, void *user_data)
vbi_page page;
int res;
char pgno_str[12];
- vbi_subno subno;
- vbi_page_type vpt;
int chop_top;
- char *lang;
+ int is_subtitle_page = ctx->subtitle_map[ev->ev.ttx_page.pgno & 0x7ff];
snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
pgno_str, ev->ev.ttx_page.subno & 0xFF);
- if (strcmp(ctx->pgno, "*") && !strstr(ctx->pgno, pgno_str))
+ if (strcmp(ctx->pgno, "*") && (strcmp(ctx->pgno, "subtitle") || !is_subtitle_page) && !strstr(ctx->pgno, pgno_str))
return;
if (ctx->handler_ret < 0)
return;
@@ -303,9 +302,7 @@ static void handler(vbi_event *ev, void *user_data)
if (!res)
return;
- vpt = vbi_classify_page(ctx->vbi, ev->ev.ttx_page.pgno, &subno, &lang);
- chop_top = ctx->chop_top ||
- ((page.rows > 1) && (vpt == VBI_SUBTITLE_PAGE));
+ chop_top = ctx->chop_top || ((page.rows > 1) && is_subtitle_page);
av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
page.columns, page.rows, chop_top);
@@ -357,11 +354,26 @@ static int slice_to_vbi_lines(TeletextContext *ctx, uint8_t* buf, int size)
else {
int line_offset = buf[2] & 0x1f;
int field_parity = buf[2] & 0x20;
- int i;
+ uint8_t *p = ctx->sliced[lines].data;
+ int i, pmag;
ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B;
ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0);
for (i = 0; i < 42; i++)
- ctx->sliced[lines].data[i] = vbi_rev8(buf[4 + i]);
+ p[i] = vbi_rev8(buf[4 + i]);
+ /* Unfortunately libzvbi does not expose page flags, and
+ * vbi_classify_page only checks MIP, so we have to manually
+ * decode the page flags and store the results. */
+ pmag = vbi_unham16p(p);
+ if (pmag >= 0 && pmag >> 3 == 0) { // We found a row 0 header
+ int page = vbi_unham16p(p + 2);
+ int flags1 = vbi_unham16p(p + 6);
+ int flags2 = vbi_unham16p(p + 8);
+ if (page >= 0 && flags1 >= 0 && flags2 >= 0) {
+ int pgno = ((pmag & 7) << 8) + page;
+ // Check for disabled NEWSFLASH flag and enabled SUBTITLE and SUPRESS_HEADER flags
+ ctx->subtitle_map[pgno] = (!(flags1 & 0x40) && flags1 & 0x80 && flags2 & 0x01);
+ }
+ }
lines++;
}
}
@@ -502,6 +514,7 @@ static int teletext_close_decoder(AVCodecContext *avctx)
vbi_decoder_delete(ctx->vbi);
ctx->vbi = NULL;
ctx->pts = AV_NOPTS_VALUE;
+ memset(ctx->subtitle_map, 0, sizeof(ctx->subtitle_map));
if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
ctx->readorder = 0;
return 0;
@@ -515,7 +528,7 @@ static void teletext_flush(AVCodecContext *avctx)
#define OFFSET(x) offsetof(TeletextContext, x)
#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
- {"txt_page", "list of teletext page numbers to decode, * is all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
+ {"txt_page", "page numbers to decode, subtitle for subtitles, * for all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
{"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
{"txt_format", "format of the subtitles (bitmap or text)", OFFSET(format_id), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD, "txt_format"},
{"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"},
diff --git a/libavcodec/version.h b/libavcodec/version.h
index b9752ce62c..5e71b48816 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -29,7 +29,7 @@
#define LIBAVCODEC_VERSION_MAJOR 58
#define LIBAVCODEC_VERSION_MINOR 20
-#define LIBAVCODEC_VERSION_MICRO 100
+#define LIBAVCODEC_VERSION_MICRO 101
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
LIBAVCODEC_VERSION_MINOR, \
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