On Tue, Jan 6, 2015 at 5:47 AM, Michael Niedermayer <michae...@gmx.at>
wrote:
> On Mon, Jan 05, 2015 at 06:20:15PM +0530, Anshul wrote:
> > On 01/04/2015 10:17 PM, Michael Niedermayer wrote:
> > > the table is constant and does not change, theres no need to have
> > > a copy of it in each context or to "make it every time decode is
> > > called"
> > > a simple static uint8_t parity_table[256];
> > > or even
> > > static const uint8_t parity_table[256] = {...}
> > >
> > done
> > >>>> + int row_cnt;
> > >>>> + struct Screen screen[2];
> > >>>> + int active_screen;
> > >>>> + uint8_t cursor_row;
> > >>>> + uint8_t cursor_column;
> > >>>> + AVBPrint buffer;
> > >>>> + int erase_display_memory;
> > >>>> + int rollup;
> > >>>> + enum cc_mode mode;
> > >>>> + int64_t start_time;
> > >>>> + /* visible screen time */
> > >>>> + int64_t startv_time;
> > >>>> + int64_t end_time;
> > >>>> + char prev_cmd[2];
> > >>>> + /* buffer to store pkt data */
> > >>>> + AVBufferRef *pktbuf;
> > >>> as you memcopy the data each time, theres no need for a AVBufferRef
> > >>> a simple uint8_t * would do the same
> > >>> but i think not even that is needed,
> > >>> all uses of the data go through process_cc608() it would be
> > >>> very simply to strip one bit in the arguments there, so no rewriting
> > >>> of the table would be needed
> > >>>
> > >>> [...]
> > >> cant do that, for error resistance we need to escape 1st byte
> > >> if parity does not match, for escaping I write 0x7f instead of
> > >> whatever data is. Some closed caption insert-er don't care much for
> parity
> > >> when they are not using the data.
> > >>
> > >> I was using AVBufferRef instead of uint8_t * , so that I don't have to
> > >> take care for length,
> > >> and length and data are in one context. and there is already lot of
> > >> error handling is
> > >> done while realloc, means I don't have to copy buffer pointer
> somewhere,
> > >> if realloc fails.
> > >> and in future if someone want to make data channel 1 and data
> channel 2
> > >> to be processed
> > >> in parallel, then he may use reference thing too.
> > >> still its my opinion, if you think uint8_t will have better
> performance,
> > >> I will change it to that.
> > > if you prefer AVBufferRef, feel free to keep using it, i dont think
> > > its the optimal choice though.
> > >
> > > Also isnt there some maximum size for these buffers ?
> > > (this would allow using a fixed size buffer and avoid the need for
> > > dealing with allocation failures)
> > >
> > There is nothing similar inside spec cc608. since its line 21 data,
> > there must
> > be something in vertical ancillary specification. I have to search for
> > that spec.
> > if you can find about max limit of vanc packet, then ccaption can not
> > exceed
> > with that.
> > >>>> +static void handle_char(CCaptionSubContext *ctx, char hi, char lo,
> int64_t pts)
> > >>>> +{
> > >>>> + struct Screen *screen = get_writing_screen(ctx);
> > >>>> + char *row = screen->characters[ctx->cursor_row] +
> ctx->cursor_column;
> > >>>> +
> > >>>> + SET_FLAG(screen->row_used,ctx->cursor_row);
> > >>>> +
> > >>>> + *row++ = hi;
> > >>>> + ctx->cursor_column++;
> > >>>> + if(lo) {
> > >>>> + *row++ = lo;
> > >>>> + ctx->cursor_column++;
> > >>>> + }
> > >>>> + *row = 0;
> > >>> this code appears to lack validity checks on the column index
> > >> Added in todo list, will do it while implementing backspace.
> > > out of array accesses are not a "todo for later" they are a
> > > critical issue that could allow an attacker to potentially execute
> > > arbitrary code, that has to be fixed before the patch can be applied
> > done, took you comment wrongly.
> > >
> > > [...]
> > >
> > >
> > >
> > >> +static int decode(AVCodecContext *avctx, void *data, int *got_sub,
> AVPacket *avpkt)
> > >> +{
> > >> + CCaptionSubContext *ctx = avctx->priv_data;
> > >> + AVSubtitle *sub = data;
> > >> + uint8_t *bptr = NULL;
> > >> + int len = avpkt->size;
> > >> + int ret = 0;
> > >> + int i;
> > >> +
> > >> + if ( ctx->pktbuf->size < len) {
> > >> + ret = av_buffer_realloc(&ctx->pktbuf, len);
> > >> + if(ret)
> > >> + len = ctx->pktbuf->size;
> > >> + }
> > > error checks in ffmpeg are <0 not != 0
> > > also i doubt that it makes sense to continue with a truncated packet
> > > and if the code does continue with a data buffer that failed to
> > > reallocate that would at least need an error/warning message so the
> > > user knows why what she sees is corrupted
> > done
> >
> > attached new patchs, for column number, I have done lots of changes,
> > you might want to reread the patch.
>
> [...]
>
> > +/**
> > + * @param ctx closed caption context just to print log
> > + */
> > +static void write_char (CCaptionSubContext *ctx, char *row, int col,
> char ch)
> > +{
> > + if(col < SCREEN_COLUMNS)
> > + row[col] = ch;
> > + /* We have extra space at end only for null character */
> > + else if ( col == SCREEN_COLUMNS && ch == 0)
> > + row[col] = ch;
> > + else
> > + av_log(ctx, AV_LOG_WARNING,"Data Ignored since exciding screen
> width\n");
> > +}
>
> The else implies that cursor_column can be an index outside the array
> handle_delete_end_of_row() uses it as index without check
> also is there something that prevents cursor_column from overflowing
> and becoming negative ? such overflow would be undefined behavior
> for a signed variable and also failing the checks above, but maybe
> iam just missing somethig and it cannot overflow
>
> done,
it cant be negative now,
changed write_char function parameter to uint8_t same as cursor_column.
for more error resistance
cursor_column is increased only if there is space to increase means only if
write_char was successful.
now handle_delete_end_of_row() is using write_char()
new patch attached
-Anshul
From f434aee902cafe45a5f36ef9a3773195cdbdef71 Mon Sep 17 00:00:00 2001
From: Anshul Maheshwari <anshul.ffm...@gmail.com>
Date: Tue, 6 Jan 2015 12:23:34 +0530
Subject: [PATCH 1/2] Adding Closed caption Support
Signed-off-by: Anshul Maheshwari <anshul.ffm...@gmail.com>
To test Closed caption use following command
ffmpeg -f lavfi -i "movie=input.ts[out0+subcc]" -map s output.srt
---
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/ccaption_dec.c | 529 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 531 insertions(+)
create mode 100644 libavcodec/ccaption_dec.c
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 107661b..33051c4 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -173,6 +173,7 @@ OBJS-$(CONFIG_BRENDER_PIX_DECODER) += brenderpix.o
OBJS-$(CONFIG_C93_DECODER) += c93.o
OBJS-$(CONFIG_CAVS_DECODER) += cavs.o cavsdec.o cavsdsp.o \
cavsdata.o mpeg12data.o
+OBJS-$(CONFIG_CCAPTION_DECODER) += ccaption_dec.o
OBJS-$(CONFIG_CDGRAPHICS_DECODER) += cdgraphics.o
OBJS-$(CONFIG_CDXL_DECODER) += cdxl.o
OBJS-$(CONFIG_CINEPAK_DECODER) += cinepak.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 8ceee2f..ef77dec 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -481,6 +481,7 @@ void avcodec_register_all(void)
/* subtitles */
REGISTER_ENCDEC (SSA, ssa);
REGISTER_ENCDEC (ASS, ass);
+ REGISTER_DECODER(CCAPTION, ccaption);
REGISTER_ENCDEC (DVBSUB, dvbsub);
REGISTER_ENCDEC (DVDSUB, dvdsub);
REGISTER_DECODER(JACOSUB, jacosub);
diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
new file mode 100644
index 0000000..a92c609
--- /dev/null
+++ b/libavcodec/ccaption_dec.c
@@ -0,0 +1,529 @@
+/*
+ * Closed Caption Decoding
+ * Copyright (c) 2015 Anshul Maheshwari
+ *
+ * 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 "avcodec.h"
+#include "ass.h"
+#include "libavutil/opt.h"
+
+#define CHAR_DEBUG
+#define SCREEN_ROWS 15
+#define SCREEN_COLUMNS 32
+
+#define SET_FLAG(var, val) ( var |= ( 1 << (val) ) )
+#define UNSET_FLAG(var, val) ( var &= ~( 1 << (val)) )
+#define CHECK_FLAG(var, val) ( (var) & (1 << (val) ) )
+
+/*
+ * TODO list
+ * 1) handle font and color completely
+ */
+enum cc_mode {
+ CCMODE_POPON,
+ CCMODE_PAINTON,
+ CCMODE_ROLLUP_2,
+ CCMODE_ROLLUP_3,
+ CCMODE_ROLLUP_4,
+ CCMODE_TEXT,
+};
+
+enum cc_color_code
+{
+ CCCOL_WHITE,
+ CCCOL_GREEN,
+ CCCOL_BLUE,
+ CCCOL_CYAN,
+ CCCOL_RED,
+ CCCOL_YELLOW,
+ CCCOL_MAGENTA,
+ CCCOL_USERDEFINED,
+ CCCOL_BLACK,
+ CCCOL_TRANSPARENT
+};
+
+enum cc_font
+{
+ CCFONT_REGULAR,
+ CCFONT_ITALICS,
+ CCFONT_UNDERLINED,
+ CCFONT_UNDERLINED_ITALICS
+};
+
+static const unsigned char pac2_attribs[][3] = // Color, font, ident
+{
+ { CCCOL_WHITE, CCFONT_REGULAR, 0 }, // 0x40 || 0x60
+ { CCCOL_WHITE, CCFONT_UNDERLINED, 0 }, // 0x41 || 0x61
+ { CCCOL_GREEN, CCFONT_REGULAR, 0 }, // 0x42 || 0x62
+ { CCCOL_GREEN, CCFONT_UNDERLINED, 0 }, // 0x43 || 0x63
+ { CCCOL_BLUE, CCFONT_REGULAR, 0 }, // 0x44 || 0x64
+ { CCCOL_BLUE, CCFONT_UNDERLINED, 0 }, // 0x45 || 0x65
+ { CCCOL_CYAN, CCFONT_REGULAR, 0 }, // 0x46 || 0x66
+ { CCCOL_CYAN, CCFONT_UNDERLINED, 0 }, // 0x47 || 0x67
+ { CCCOL_RED, CCFONT_REGULAR, 0 }, // 0x48 || 0x68
+ { CCCOL_RED, CCFONT_UNDERLINED, 0 }, // 0x49 || 0x69
+ { CCCOL_YELLOW, CCFONT_REGULAR, 0 }, // 0x4a || 0x6a
+ { CCCOL_YELLOW, CCFONT_UNDERLINED, 0 }, // 0x4b || 0x6b
+ { CCCOL_MAGENTA, CCFONT_REGULAR, 0 }, // 0x4c || 0x6c
+ { CCCOL_MAGENTA, CCFONT_UNDERLINED, 0 }, // 0x4d || 0x6d
+ { CCCOL_WHITE, CCFONT_ITALICS, 0 }, // 0x4e || 0x6e
+ { CCCOL_WHITE, CCFONT_UNDERLINED_ITALICS, 0 }, // 0x4f || 0x6f
+ { CCCOL_WHITE, CCFONT_REGULAR, 0 }, // 0x50 || 0x70
+ { CCCOL_WHITE, CCFONT_UNDERLINED, 0 }, // 0x51 || 0x71
+ { CCCOL_WHITE, CCFONT_REGULAR, 4 }, // 0x52 || 0x72
+ { CCCOL_WHITE, CCFONT_UNDERLINED, 4 }, // 0x53 || 0x73
+ { CCCOL_WHITE, CCFONT_REGULAR, 8 }, // 0x54 || 0x74
+ { CCCOL_WHITE, CCFONT_UNDERLINED, 8 }, // 0x55 || 0x75
+ { CCCOL_WHITE, CCFONT_REGULAR, 12 }, // 0x56 || 0x76
+ { CCCOL_WHITE, CCFONT_UNDERLINED, 12 }, // 0x57 || 0x77
+ { CCCOL_WHITE, CCFONT_REGULAR, 16 }, // 0x58 || 0x78
+ { CCCOL_WHITE, CCFONT_UNDERLINED, 16 }, // 0x59 || 0x79
+ { CCCOL_WHITE, CCFONT_REGULAR, 20 }, // 0x5a || 0x7a
+ { CCCOL_WHITE, CCFONT_UNDERLINED, 20 }, // 0x5b || 0x7b
+ { CCCOL_WHITE, CCFONT_REGULAR, 24 }, // 0x5c || 0x7c
+ { CCCOL_WHITE, CCFONT_UNDERLINED, 24 }, // 0x5d || 0x7d
+ { CCCOL_WHITE, CCFONT_REGULAR, 28 }, // 0x5e || 0x7e
+ { CCCOL_WHITE, CCFONT_UNDERLINED, 28 } // 0x5f || 0x7f
+ /* total 32 entry */
+};
+/* 0-255 needs 256 space */
+static const uint8_t parity_table[256] = { 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0 };
+struct Screen {
+ /* +1 is used to compensate null character of string */
+ uint8_t characters[SCREEN_ROWS][SCREEN_COLUMNS+1];
+ /*
+ * Bitmask of used rows; if a bit is not set, the
+ * corresponding row is not used.
+ * for setting row 1 use row | (0 << 1)
+ * for setting row 15 use row | (1 << 14)
+ */
+ int16_t row_used;
+};
+
+
+typedef struct CCaptionSubContext {
+ AVClass *class;
+ int row_cnt;
+ struct Screen screen[2];
+ int active_screen;
+ uint8_t cursor_row;
+ uint8_t cursor_column;
+ uint8_t cursor_color;
+ uint8_t cursor_font;
+ AVBPrint buffer;
+ int erase_display_memory;
+ int rollup;
+ enum cc_mode mode;
+ int64_t start_time;
+ /* visible screen time */
+ int64_t startv_time;
+ int64_t end_time;
+ char prev_cmd[2];
+ /* buffer to store pkt data */
+ AVBufferRef *pktbuf;
+}CCaptionSubContext;
+
+
+static av_cold int init_decoder(AVCodecContext *avctx)
+{
+ int ret;
+ CCaptionSubContext *ctx = avctx->priv_data;
+
+ av_bprint_init(&ctx->buffer, 0, AV_BPRINT_SIZE_UNLIMITED);
+ /* taking by default roll up to 2 */
+ ctx->rollup = 2;
+ ret = ff_ass_subtitle_header_default(avctx);
+ /* allocate pkt buffer */
+ ctx->pktbuf = av_buffer_alloc(128);
+ if( !ctx->pktbuf) {
+ ret = AVERROR(ENOMEM);
+ }
+
+
+ return ret;
+}
+
+static av_cold int close_decoder(AVCodecContext *avctx)
+{
+ CCaptionSubContext *ctx = avctx->priv_data;
+ av_bprint_finalize( &ctx->buffer, NULL);
+ av_buffer_unref(&ctx->pktbuf);
+ return 0;
+}
+/**
+ * @param ctx closed caption context just to print log
+ */
+static int write_char (CCaptionSubContext *ctx, char *row,uint8_t col, char ch)
+{
+ if(col < SCREEN_COLUMNS) {
+ row[col] = ch;
+ return 0;
+ }
+ /* We have extra space at end only for null character */
+ else if ( col == SCREEN_COLUMNS && ch == 0) {
+ row[col] = ch;
+ return 0;
+ }
+ else {
+ av_log(ctx, AV_LOG_WARNING,"Data Ignored since exciding screen width\n");
+ return AVERROR_INVALIDDATA;
+ }
+}
+/**
+ * This function after validating parity bit, also remove it from data pair.
+ * The first byte doesn't pass parity, we replace it with a solid blank
+ * and process the pair.
+ * If the second byte doesn't pass parity, it returns INVALIDDATA
+ * user can ignore the whole pair and pass the other pair.
+ */
+static int validate_cc_data_pair (uint8_t *cc_data_pair)
+{
+ uint8_t cc_valid = (*cc_data_pair & 4) >>2;
+ uint8_t cc_type = *cc_data_pair & 3;
+
+ if (!cc_valid)
+ return AVERROR_INVALIDDATA;
+
+ // if EIA-608 data then verify parity.
+ if (cc_type==0 || cc_type==1) {
+ if (!parity_table[cc_data_pair[2]]) {
+ return AVERROR_INVALIDDATA;
+ }
+ if (!parity_table[cc_data_pair[1]]) {
+ cc_data_pair[1]=0x7F;
+ }
+ }
+
+ //Skip non-data
+ if( (cc_data_pair[0] == 0xFA || cc_data_pair[0] == 0xFC || cc_data_pair[0] == 0xFD )
+ && (cc_data_pair[1] & 0x7F) == 0 && (cc_data_pair[2] & 0x7F) == 0)
+ return AVERROR_PATCHWELCOME;
+
+ //skip 708 data
+ if(cc_type == 3 || cc_type == 2 )
+ return AVERROR_PATCHWELCOME;
+
+ /* remove parity bit */
+ cc_data_pair[1] &= 0x7F;
+ cc_data_pair[2] &= 0x7F;
+
+
+ return 0;
+
+}
+
+static struct Screen *get_writing_screen(CCaptionSubContext *ctx)
+{
+ switch (ctx->mode) {
+ case CCMODE_POPON:
+ // use Inactive screen
+ return ctx->screen + !ctx->active_screen;
+ case CCMODE_PAINTON:
+ case CCMODE_ROLLUP_2:
+ case CCMODE_ROLLUP_3:
+ case CCMODE_ROLLUP_4:
+ case CCMODE_TEXT:
+ // use active screen
+ return ctx->screen + ctx->active_screen;
+ }
+ /* It was never an option */
+ return NULL;
+}
+
+static void handle_textattr( CCaptionSubContext *ctx, uint8_t hi, uint8_t lo )
+{
+ int i = lo - 0x20;
+ int ret;
+ struct Screen *screen = get_writing_screen(ctx);
+ char *row = screen->characters[ctx->cursor_row];
+
+ if( i >= 32)
+ return;
+
+ ctx->cursor_color = pac2_attribs[i][0];
+ ctx->cursor_font = pac2_attribs[i][1];
+
+ SET_FLAG(screen->row_used,ctx->cursor_row);
+ ret = write_char(ctx, row, ctx->cursor_column, ' ');
+ if(ret == 0)
+ ctx->cursor_column++;
+}
+static void handle_pac( CCaptionSubContext *ctx, uint8_t hi, uint8_t lo )
+{
+ static const int8_t row_map[] = {
+ 11, -1, 1, 2, 3, 4, 12, 13, 14, 15, 5, 6, 7, 8, 9, 10
+ };
+ const int index = ( (hi<<1) & 0x0e) | ( (lo>>5) & 0x01 );
+ struct Screen *screen = get_writing_screen(ctx);
+ char *row;
+ int indent,i,ret;
+
+ if( row_map[index] <= 0 )
+ return;
+
+ lo &= 0x1f;
+
+ ctx->cursor_row = row_map[index] - 1;
+ ctx->cursor_color = pac2_attribs[lo][0];
+ ctx->cursor_font = pac2_attribs[lo][1];
+ ctx->cursor_column = 0;
+ indent = pac2_attribs[lo][2];
+ row = screen->characters[ctx->cursor_row];
+ for(i = 0;i < indent; i++) {
+ ret = write_char(ctx, row, ctx->cursor_column, ' ');
+ if( ret == 0 )
+ ctx->cursor_column++;
+ }
+
+}
+
+/**
+ * @param pts it is required to set end time
+ */
+static int handle_edm(CCaptionSubContext *ctx,int64_t pts)
+{
+ int i;
+ int ret = 0;
+ struct Screen *screen = ctx->screen + ctx->active_screen;
+
+ ctx->start_time = ctx->startv_time;
+ for( i = 0; screen->row_used && i < SCREEN_ROWS; i++)
+ {
+ if(CHECK_FLAG(screen->row_used,i)) {
+ char *str = screen->characters[i];
+ /* skip space */
+ while (*str == ' ')
+ str++;
+ av_bprint_append_data(&ctx->buffer, str, strlen(str));
+ av_bprint_append_data(&ctx->buffer, "\\N",2);
+ UNSET_FLAG(screen->row_used, i);
+ ret = av_bprint_is_complete(&ctx->buffer);
+ if( ret == 0) {
+ ret = AVERROR(ENOMEM);
+ break;
+ }
+ }
+
+ }
+ ctx->startv_time = pts;
+ ctx->erase_display_memory = 1;
+ ctx->end_time = pts;
+ return ret;
+}
+static int handle_eoc(CCaptionSubContext *ctx, int64_t pts)
+{
+ int ret;
+ ret = handle_edm(ctx,pts);
+ ctx->active_screen = !ctx->active_screen;
+ ctx->cursor_column = 0;
+ return ret;
+}
+static void handle_delete_end_of_row( CCaptionSubContext *ctx, char hi, char lo)
+{
+ struct Screen *screen = get_writing_screen(ctx);
+ char *row = screen->characters[ctx->cursor_row];
+ write_char(ctx, row, ctx->cursor_column, 0);
+
+}
+static void handle_char(CCaptionSubContext *ctx, char hi, char lo, int64_t pts)
+{
+ struct Screen *screen = get_writing_screen(ctx);
+ char *row = screen->characters[ctx->cursor_row];
+ int ret;
+
+ SET_FLAG(screen->row_used,ctx->cursor_row);
+
+ ret = write_char(ctx, row, ctx->cursor_column, hi);
+ if( ret == 0 )
+ ctx->cursor_column++;
+
+ if(lo) {
+ ret = write_char(ctx, row, ctx->cursor_column, lo);
+ if ( ret == 0 )
+ ctx->cursor_column++;
+ }
+ write_char(ctx, row, ctx->cursor_column, 0);
+
+ /* reset prev command since character can repeat */
+ ctx->prev_cmd[0] = 0;
+ ctx->prev_cmd[1] = 0;
+#ifdef CHAR_DEBUG
+ av_log(ctx, AV_LOG_DEBUG,"(%c,%c)\n",hi,lo);
+#endif
+}
+static int process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint8_t lo)
+{
+ int ret = 0;
+#define COR3(var, with1, with2, with3) ( (var) == (with1) || (var) == (with2) || (var) == (with3) )
+ if ( hi == ctx->prev_cmd[0] && lo == ctx->prev_cmd[1]) {
+ /* ignore redundant command */
+ } else if ( (hi == 0x10 && (lo >= 0x40 || lo <= 0x5f)) ||
+ ( (hi >= 0x11 && hi <= 0x17) && (lo >= 0x40 && lo <= 0x7f) ) ) {
+ handle_pac(ctx, hi, lo);
+ } else if ( ( hi == 0x11 && lo >= 0x20 && lo <= 0x2f ) ||
+ ( hi == 0x17 && lo >= 0x2e && lo <= 0x2f) ) {
+ handle_textattr(ctx, hi, lo);
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x20 ) {
+ /* resume caption loading */
+ ctx->mode = CCMODE_POPON;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x24 ) {
+ handle_delete_end_of_row(ctx, hi, lo);
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x25 ) {
+ ctx->rollup = 2;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x26 ) {
+ ctx->rollup = 3;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x27 ) {
+ ctx->rollup = 4;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x29 ) {
+ /* resume direct captioning */
+ ctx->mode = CCMODE_PAINTON;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2B ) {
+ /* resume text display */
+ ctx->mode = CCMODE_TEXT;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2C ) {
+ /* erase display memory */
+ ret = handle_edm(ctx, pts);
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2D ) {
+ /* carriage return */
+ ctx->row_cnt++;
+ if(ctx->row_cnt >= ctx->rollup) {
+ ctx->row_cnt = 0;
+ ret = handle_edm(ctx, pts);
+ ctx->active_screen = !ctx->active_screen;
+ }
+ ctx->cursor_column = 0;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2F ) {
+ /* end of caption */
+ ret = handle_eoc(ctx, pts);
+ } else if (hi>=0x20) {
+ /* Standard characters (always in pairs) */
+ handle_char(ctx, hi, lo, pts);
+ } else {
+ /* Ignoring all other non data code */
+ }
+
+ /* set prev command */
+ ctx->prev_cmd[0] = hi;
+ ctx->prev_cmd[1] = lo;
+
+#undef COR3
+ return ret;
+
+}
+static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
+{
+ CCaptionSubContext *ctx = avctx->priv_data;
+ AVSubtitle *sub = data;
+ uint8_t *bptr = NULL;
+ int len = avpkt->size;
+ int ret = 0;
+ int i;
+
+ if ( ctx->pktbuf->size < len) {
+ ret = av_buffer_realloc(&ctx->pktbuf, len);
+ if(ret < 0) {
+ av_log(ctx, AV_LOG_WARNING, "Insufficient Memory of %d truncated to %d\n",len, ctx->pktbuf->size);
+ len = ctx->pktbuf->size;
+ ret = 0;
+ }
+ }
+ memcpy(ctx->pktbuf->data, avpkt->data, len);
+ bptr = ctx->pktbuf->data;
+
+
+ for (i = 0; i < len; i += 3) {
+ uint8_t cc_type = *(bptr + i) & 3;
+ if (validate_cc_data_pair( bptr + i) )
+ continue;
+ /* ignoring data field 1 */
+ if(cc_type == 1)
+ continue;
+ else
+ process_cc608(ctx, avpkt->pts, *(bptr + i + 1) & 0x7f, *(bptr + i + 2) & 0x7f);
+ if(ctx->erase_display_memory && *ctx->buffer.str)
+ {
+ int start_time = av_rescale_q(ctx->start_time, avctx->time_base, (AVRational){ 1, 100 });
+ int end_time = av_rescale_q(ctx->end_time, avctx->time_base, (AVRational){ 1, 100 });
+#ifdef CHAR_DEBUG
+ av_log(ctx, AV_LOG_DEBUG,"cdp writing data (%s)\n",ctx->buffer.str);
+#endif
+ ret = ff_ass_add_rect(sub, ctx->buffer.str, start_time, end_time - start_time , 0);
+ if (ret < 0)
+ return ret;
+ sub->pts = av_rescale_q(ctx->start_time, avctx->time_base, AV_TIME_BASE_Q);
+ ctx->erase_display_memory = 0;
+ av_bprint_clear(&ctx->buffer);
+ }
+ }
+
+ *got_sub = sub->num_rects > 0;
+ return ret;
+}
+static const AVOption options[] = {
+ {NULL}
+};
+static const AVClass ccaption_dec_class = {
+ .class_name = "Closed caption Decoder",
+ .item_name = av_default_item_name,
+ .option = options,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
+AVCodec ff_ccaption_decoder = {
+ .name = "cc_dec",
+ .long_name = NULL_IF_CONFIG_SMALL("Closed Caption (EIA-608 / CEA-708) Decoder"),
+ .type = AVMEDIA_TYPE_SUBTITLE,
+ .id = AV_CODEC_ID_EIA_608,
+ .priv_data_size = sizeof(CCaptionSubContext),
+ .init = init_decoder,
+ .close = close_decoder,
+ .decode = decode,
+ .priv_class = &ccaption_dec_class,
+};
--
1.8.1.4
From bd9c4c442e5a15e3c12797cc4f7c85881a805122 Mon Sep 17 00:00:00 2001
From: Anshul Maheshwari <anshul.ffm...@gmail.com>
Date: Tue, 6 Jan 2015 12:25:41 +0530
Subject: [PATCH 2/2] Adding Closed caption accessories
Signed-off-by: Anshul Maheshwari <anshul.ffm...@gmail.com>
---
Changelog | 1 +
MAINTAINERS | 1 +
libavcodec/version.h | 2 +-
3 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/Changelog b/Changelog
index 37ce0f0..d4efd74 100644
--- a/Changelog
+++ b/Changelog
@@ -9,6 +9,7 @@ version <next>:
- RTP/mpegts muxer
- non continuous cache protocol support
- tblend filter
+- Closed caption Decoder
version 2.5:
diff --git a/MAINTAINERS b/MAINTAINERS
index 6e46280..13b211e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -156,6 +156,7 @@ Codecs:
celp_filters.* Vitor Sessak
cinepak.c Roberto Togni
cinepakenc.c Rl / Aetey G.T. AB
+ ccaption_dec.c Anshul Maheshwari
cljr Alex Beregszaszi
cllc.c Derek Buitenhuis
cook.c, cookdata.h Benjamin Larsson
diff --git a/libavcodec/version.h b/libavcodec/version.h
index d8c891d..7e51f3b 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -29,7 +29,7 @@
#include "libavutil/version.h"
#define LIBAVCODEC_VERSION_MAJOR 56
-#define LIBAVCODEC_VERSION_MINOR 19
+#define LIBAVCODEC_VERSION_MINOR 20
#define LIBAVCODEC_VERSION_MICRO 100
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
--
1.8.1.4
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