On 01/03/2015 01:42 AM, Michael Niedermayer wrote:
> On Wed, Dec 31, 2014 at 07:09:33PM +0530, Anshul wrote:
> [...]
>
>> +static void build_parity_table(int *parity_table)
>> +{
>> + unsigned int byte;
>> + int parity_v;
>> + for (byte = 0; byte <= 127; byte++) {
>> + parity_v = av_popcount(byte) & 1;
>> + parity_table[byte] = parity_v;
>> + parity_table[byte | 0x80] = !parity_v;
>> + }
>> +}
> This should not be needed, av_popcount(byte) & 1 could be used
> directly or you could use something like this: (untested)
> (0x6996 >> ((byte ^ (byte>>4)) & 15)) & 1
>
> the code using the parity stuff does not seem speed critical
> but maybe iam missing something ?
parity is checked for each byte of data in closed caption, so I thought
it would be speed critical. only 7 bits are used in each byte. 1 bit is
fr parity.
> [...]
>
>> +static void handle_pac( CCaptionSubContext *ctx, uint8_t hi, uint8_t lo )
>> +{
>> + static const uint8_t row_map[] = {
>> + 11, -1, 1, 2, 3, 4, 12, 13, 14, 15, 5, 6, 7, 8, 9, 10
>> + };
> you are having negative values in a unsigned 8bit table
> i assume either of these is not intended
done, -1 was needed.
changed uint8_t to int8_t
>
> [...]
>> +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 ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x20 ) {
>> + /* resume caption loading */
>> + ctx->mode = CCMODE_POPON;
>> + } 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 == 0x2C ) {
>> + /* erase display memory */
>> + ret = handle_edm(ctx, pts);
>> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2D ) {
>> + /* carriage return */
>> + av_log(ctx, AV_LOG_DEBUG,"cdp (handle cr)\n");
>> + ctx->row_cnt++;
>> + if(ctx->row_cnt == ctx->rollup) {
>> + ctx->row_cnt = 0;
>> + ret = handle_edm(ctx, pts);
>> + ctx->active_screen = !ctx->active_screen;
>> + }
>> + } 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 = avpkt->data;
> The input packets data is read only unless you do something
> (dup/memcpy/whatever) so this should be const
copied data in AVbufferRef.
>
>> + int len = avpkt->size;
>> + int ret = 0;
>> + int i;
>> +
>> + for (i = 0; i < len; i += 3) {
>> + uint8_t cc_type = *(bptr + i) & 3;
>> + if (validate_cc_data_pair( bptr + i, ctx->parity_table ) )
>> + continue;
>> + /* ignoring data field 1 */
>> + if(cc_type == 1)
>> + continue;
>> + else
>> + process_cc608(ctx, avpkt->pts, *(bptr + i + 1), *(bptr + i +
>> 2));
>> + }
>> + 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 });
>> + av_log(ctx, AV_LOG_DEBUG,"cdp writing data (%s)\n",ctx->buffer.str);
> tabs, also theres a alot of deug av_logs in the code, it might make
> sense to remove or disable these before its pushed
most of the logs I have removed, others I have disabled.
I have attached 2 pacth 1 improvement of this other is info regarding
1st one.
-Anshul
>From 17a564409b84fc18293833cc3f2151792209bb8b Mon Sep 17 00:00:00 2001
From: Anshul Maheshwari <anshul.ffm...@gmail.com>
Date: Sat, 3 Jan 2015 12:40:35 +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=/home/a141982112/test_videos/Starship_Troopers.vob[out0+subcc]" -map s some.srt
---
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/ccaption_dec.c | 361 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 363 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..d351efe
--- /dev/null
+++ b/libavcodec/ccaption_dec.c
@@ -0,0 +1,361 @@
+/*
+ * Closed Caption Decoding
+ * Copyright (c) 2014 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"
+
+#undef 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) ) )
+
+enum cc_mode {
+ CCMODE_POPON,
+ CCMODE_PAINTON,
+ CCMODE_ROLLUP_2,
+ CCMODE_ROLLUP_3,
+ CCMODE_ROLLUP_4,
+ CCMODE_TEXT,
+};
+
+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 parity_table[256];
+ 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;
+}CCaptionSubContext;
+
+static void build_parity_table(int *parity_table)
+{
+ unsigned int byte;
+ int parity_v;
+ for (byte = 0; byte <= 127; byte++) {
+ parity_v = av_popcount(byte) & 1;
+ parity_table[byte] = parity_v;
+ parity_table[byte | 0x80] = !parity_v;
+ }
+}
+
+static av_cold int init_decoder(AVCodecContext *avctx)
+{
+ int ret;
+ CCaptionSubContext *ctx = avctx->priv_data;
+
+ build_parity_table(ctx->parity_table);
+ 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;
+}
+
+/**
+ * This function after validating parity bit, also remove it from data pair.
+ */
+static int validate_cc_data_pair (uint8_t *cc_data_pair, int *parity_table)
+{
+ 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]]) {
+ // If the second byte doesn't pass parity, ignore pair
+ return AVERROR_INVALIDDATA;
+ }
+ if (!parity_table[cc_data_pair[1]]) {
+ // The first byte doesn't pass parity, we replace it with a solid blank
+ // and process the pair.
+ 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 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 );
+
+ if( row_map[index] <= 0 )
+ return;
+
+ ctx->cursor_row = row_map[index] - 1;
+ ctx->cursor_column = 0;
+
+}
+
+/**
+ * @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)) {
+ av_bprint_append_data(&ctx->buffer, screen->characters[i], strlen(screen->characters[i]));
+ av_bprint_append_data(&ctx->buffer, "\\N",2);
+ UNSET_FLAG(screen->row_used, i);
+ ret = av_bprint_is_complete(&ctx->buffer);
+ if( ret) {
+ 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;
+ return ret;
+}
+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_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;
+ /* 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 ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x20 ) {
+ /* resume caption loading */
+ ctx->mode = CCMODE_POPON;
+ } 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 == 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;
+ }
+ } 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)
+ len = ctx->pktbuf->size;
+ }
+ 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, ctx->parity_table ) )
+ continue;
+ /* ignoring data field 1 */
+ if(cc_type == 1)
+ continue;
+ else
+ process_cc608(ctx, avpkt->pts, *(bptr + i + 1), *(bptr + i + 2));
+ }
+ 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 0;
+}
+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 e0c5ebb592d33c05446dcab019e5a2cb14185569 Mon Sep 17 00:00:00 2001
From: Anshul Maheshwari <anshul.ffm...@gmail.com>
Date: Sat, 3 Jan 2015 12:48:37 +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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