On 12/30/2014 11:13 PM, Michael Niedermayer wrote:
> On Tue, Dec 30, 2014 at 07:46:29PM +0530, Anshul wrote:
>> On 12/12/2014 04:23 PM, Anshul wrote:
>>> On 12/06/2014 04:24 PM, Anshul wrote:
>>>> On 12/06/2014 04:22 PM, Anshul wrote:
>>>>> On 12/05/2014 07:56 PM, Nicolas George wrote:
>>>>>> Hi. I had time to look at the code with some more details. Comments are
>>>>>> below.
>>>>>>
>>>>>>> >From 31f69ccfb45247a7cc203084a931b8523284aa13 Mon Sep 17 00:00:00 2001
>>>>>>> From: Anshul Maheshwari <anshul.ffm...@gmail.com>
>>>>>>> Date: Wed, 3 Dec 2014 23:37:22 +0530
>>>>>>> Subject: [PATCH 2/2] Adding Closed caption Decoder
>>>>>>>
>>>>>>> ---
>>>>>>> libavcodec/Makefile | 1 +
>>>>>>> libavcodec/allcodecs.c | 1 +
>>>>>>> libavcodec/ccaption_dec.c | 318
>>>>>>> ++++++++++++++++++++++++++++++++++++++++++++++
>>>>>>> 3 files changed, 320 insertions(+)
>>>>>>> create mode 100644 libavcodec/ccaption_dec.c
>>>>>>>
>>>>>>> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
>>>>>>> index fa0f53d..bbc516d 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 0d39d33..8c07388 100644
>>>>>>> --- a/libavcodec/allcodecs.c
>>>>>>> +++ b/libavcodec/allcodecs.c
>>>>>>> @@ -480,6 +480,7 @@ 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..0a7dfd8
>>>>>>> --- /dev/null
>>>>>>> +++ b/libavcodec/ccaption_dec.c
>>>>>>> @@ -0,0 +1,318 @@
>>>>>>> +/*
>>>>>>> + * 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"
>>>>>>> +
>>>>>>> +#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 {
>>>>>>> + uint8_t characters[SCREEN_ROWS][SCREEN_COLUMNS+1];
>>>>>> Maybe add a comment about the +1?
>>>>> done
>>>>>>> + /*
>>>>>>> + * row used flag will be 0 when none in use other wise it will
>>>>>>> have its
>>>>>>> + * corrosponding bit high.
>>>>>> Language nit. I suggest: "Bitmask of used rows; if a bit is not set, the
>>>>>> corresponding row is not used."
>>>>> done
>>>>>>> + * for setting row 1 use row | (1 >> 1)
>>>>>>> + * for setting row 15 use row | (1 >> 15)
>>>>>> Are you sure that is ">>" and not "<<"? And is it a good idea to number
>>>>>> starting from 1?
>>>>> It was just commented in wrong way, corrected comment.
>>>>>>> + */
>>>>>>> + int16_t row_used;
>>>>>>> +};
>>>>>>> +
>>>>>>> +
>>>>>>> +typedef struct CCaptionSubContext {
>>>>>>> + int parity_table[256];
>>>>>>> + int row_cnt;
>>>>>>> + struct Screen screen[2];
>>>>>>> + int active_screen;
>>>>>>> + int cursor_row;
>>>>>>> + int cursor_column;
>>>>>>> + AVBPrint buffer;
>>>>>>> + /* erase display memory */
>>>>>>> + int edm;
>>>>>> It is used only a handful of times: I suggest a more meaningful name
>>>>>> instead
>>>>>> of a comment: "erase_disp_mem" for example.
>>>>> done
>>>>>>> + int rollup;
>>>>>>> + enum cc_mode mode;
>>>>>>> + int64_t start_time;
>>>>>>> + /* visible screen time */
>>>>>>> + int64_t startv_time;
>>>>>> Is the v a typo?
>>>>> no it was written to express v = visible, (visible screen start time)
>>>>>>> + int64_t end_time;
>>>>>>> + char prev_cmd[2];
>>>>>> The code uses various types for these values: char, unsigned char,
>>>>>> uint8_t.
>>>>>> I suggest to stick with uint8_t if it works.
>>>>> changed unsigned char to uint8_t
>>>>>>> +}CCaptionSubContext;
>>>>>>> +
>>>>>>> +static void build_parity_table(int *parity_table)
>>>>>>> +{
>>>>>>> + unsigned int byte;
>>>>>> Inconsistent indentation.
>>>>> corrected
>>>>>>> + int parity_v;
>>>>>>> + for (byte = 0; byte <= 127; byte++) {
>>>>>>> + parity_v = av_popcount(byte & 0x7f) & 1;
>>>>>> The & 0x7f is redundant.
>>>>> removed
>>>>>>> + parity_table[byte] = parity_v;
>>>>>>> + parity_table[byte | 0x80] = !parity_v;
>>>>>>> + }
>>>>>>> +}
>>>>>>> +
>>>>>>> +static av_cold int init_decoder(AVCodecContext *avctx)
>>>>>>> +{
>>>>>>> +
>>>>>>> + CCaptionSubContext *ctx = avctx->priv_data;
>>>>>>> +
>>>>>>> + build_parity_table(ctx->parity_table);
>>>>>>> + ctx->row_cnt = 0;
>>>>>>> + av_bprint_init(&ctx->buffer, 0, AV_BPRINT_SIZE_UNLIMITED);
>>>>>>> + ctx->edm = 0;
>>>>>>> + /* taking by default roll up to 2 */
>>>>>>> + ctx->rollup = 2;
>>>>>>> + /* set active screen as 0 */
>>>>>>> + ctx->active_screen = 0;
>>>>>>> + memset(ctx->prev_cmd,0,2);
>>>>>>> + ff_ass_subtitle_header_default(avctx);
>>>>>> All the "= 0" and the memset are unnecessary.
>>>>> removed
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +static av_cold int close_decoder(AVCodecContext *avctx)
>>>>>>> +{
>>>>>>> + CCaptionSubContext *ctx = avctx->priv_data;
>>>>>>> + av_bprint_finalize( &ctx->buffer, NULL);
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +/**
>>>>>>> + * This function after validating parity bit, also remove it from data
>>>>>>> pair.
>>>>>>> + */
>>>>>>> +static int validate_cc_data_pair (unsigned char *cc_data_pair, int
>>>>>>> *parity_table)
>>>>>>> +{
>>>>>>> + unsigned char cc_valid = (*cc_data_pair & 4) >>2;
>>>>>>> + unsigned char cc_type = *cc_data_pair & 3;
>>>>>>> +
>>>>>>> + if (!cc_valid)
>>>>>>> + return -1;
>>>>>>> +
>>>>>>> + // 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 -1;
>>>>>> Meaningful error codes? AVERROR(EINVAL) or AVERROR_INVALID_DATA? Even
>>>>>> when
>>>>>> they are not supposed to, the -1 have a habit of reaching the user. Same
>>>>>> below.
>>>>> done
>>>>>>> + }
>>>>>>> + 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 -1;
>>>>>>> +
>>>>>>> + //skip 708 data
>>>>>>> + if(cc_type == 3 || cc_type == 2 )
>>>>>>> + return -1;
>>>>>>> +
>>>>>>> + /* 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 int row_map[] = {
>>>>>> Could be int8_t to save memory.
>>>>> done
>>>>>>> + 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 );
>>>>>>> +
>>>>>> It looks like the values come from external data with subtle arithmetic,
>>>>>> so
>>>>>> I suggest:
>>>>>>
>>>>>> av_assert2((unsigned)index < sizeof(row_map));
>>>>> I am using 3 bit from hi and 1 bit from lo data, so I am using total 4 bit
>>>>> which mean only 0-15 possible. and for unknown value not defined in spec
>>>>> I have kept the value as -1 on that index.
>>>>> so no need to check.
>>>>>>> + 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 void handle_edm(CCaptionSubContext *ctx,int64_t pts)
>>>>>>> +{
>>>>>>> + int i;
>>>>>>> + 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);
>>>>>>> + }
>>>>>>> + }
>>>>>>> + ctx->startv_time = pts;
>>>>>>> + ctx->edm = 1;
>>>>>>> + ctx->end_time = pts;
>>>>>>> +}
>>>>>>> +static void handle_eoc(CCaptionSubContext *ctx, int64_t pts)
>>>>>>> +{
>>>>>>> + ctx->active_screen = !ctx->active_screen;
>>>>>>> + ctx->startv_time = pts;
>>>>>>> +}
>>>>>>> +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;
>>>>>> Here too: av_assert0((unsigned)ctx->cursor_row < SCREEN_ROWS) and same
>>>>>> for
>>>>>> column.
>>>>> We can never get row greater then SCREEN_ROWS, I have not implemented to
>>>>> read column value from pac. so left it as it is.
>>>>>>> +
>>>>>>> + 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;
>>>>>>> +}
>>>>>>> +static int process_cc608(CCaptionSubContext *ctx, int64_t pts,
>>>>>>> unsigned char hi, unsigned char lo)
>>>>>>> +{
>>>>>>> +
>>>>>>> +#define COR3(var, with1, with2, with3) ( (var) == (with1) || (var)
>>>>>>> == (with2) || (var) == (with3) )
>>>>>> It looks like you always use COR3(hi, 0x14, 0x15, 0x1C) exactly: is it on
>>>>>> purpose, a typo, or maybe can you simplify?
>>>>> These are done for purpose, I have to implement some other command which
>>>>> have
>>>>> different values to be compared. so not simplifying it.
>>>>>>> + 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 */
>>>>>>> + 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;
>>>>>>> + handle_edm(ctx, pts);
>>>>>>> + }
>>>>>>> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2F ) {
>>>>>>> + /* end of caption */
>>>>>>> + 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 0;
>>>>>>> +
>>>>>>> +}
>>>>>>> +static int decode(AVCodecContext *avctx, void *data, int *got_sub,
>>>>>>> AVPacket *avpkt)
>>>>>>> +{
>>>>>>> + CCaptionSubContext *ctx = avctx->priv_data;
>>>>>>> + AVSubtitle *sub = data;
>>>>>>> + unsigned char *bptr = avpkt->data;
>>>>>>> + int len = avpkt->size;
>>>>>>> + int ret = 0;
>>>>>>> + int i;
>>>>>>> +
>>>>>>> + for (i = 0; i < len; i += 3) {
>>>>>>> + unsigned char 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->edm && *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 });
>>>>>>> + ret = ff_ass_add_rect(sub, ctx->buffer.str, start_time,
>>>>>>> end_time - start_time , 0);
>>>>>>> a
>>>>>> You need to use av_bprint_is_complete() and return AVERROR(ENOMEM) if the
>>>>>> text was truncated.
>>>>> done in handle_edm
>>>>>>> + if (ret < 0)
>>>>>>> + return ret;
>>>>>>> + sub->pts = av_rescale_q(ctx->start_time, avctx->time_base,
>>>>>>> AV_TIME_BASE_Q);
>>>>>>> + ctx->edm = 0;
>>>>>>> + av_bprint_clear(&ctx->buffer);
>>>>>>> + }
>>>>>>> +
>>>>>>> + *got_sub = sub->num_rects > 0;
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +AVCodec ff_ccaption_decoder = {
>>>>>>> + .name = "cc_dec",
>>>>>>> + .long_name = NULL_IF_CONFIG_SMALL("Closed Caption Decoder"),
>>>>>> I suggest to have "EIA-608" and "CEA-708" appear in the name, for people
>>>>>> specifically looking for it: "Closed Caption (EIA-608 / CEA-708) Decoder"
>>>>>> maybe.
>>>>> done
>>>>>>> + .type = AVMEDIA_TYPE_SUBTITLE,
>>>>>>> + .id = AV_CODEC_ID_EIA_608,
>>>>>>> + .priv_data_size = sizeof(CCaptionSubContext),
>>>>>>> + .init = init_decoder,
>>>>>>> + .close = close_decoder,
>>>>>>> + .decode = decode,
>>>>>>> +};
>>>>>> Regards,
>>>>>>
>>>>> I have also removed some error which were causing to print nothing in
>>>>> subccItalic.mpg.
>>>>>
>>>>> Though subtitle is still not italic.
>>>>>
>>>>> I was thinking to put extra features in next iteration of patch.
>>>>>
>>>>> -Anshul
>>>>>
>>>> Attaching patch with those work.
>>> ping
>>>
>>> -please comment
>>> Anshul Maheshwari
>> ping
> missing testcase (yes i want to test it before applying)
> please make sure theres a testcase in the comit message
> note, i am to dumb to find testcases in the middle of threads (in case
> there was one)
> also if the testcase or the patch as a whole depends on other patches
> dont forget to metion these
>
> missing signoff
> see: http://ltsi.linuxfoundation.org/developers/signed-process
> for the approximate idea behind signing off patches
>
> [...]
>
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
I have attached new patch with signoff, and some other debug logs added.
I have also attached the other patch on which this depend, but if you
want to search in mails
Then nicolas submitted the same patch on 4th December.
You can use Starship_Troopers.vob video file for testing this decoder,
its in sample/ccaption folder
dont know exact location, but its the same video using which we test dvb
subtitle.
-Anshul
>From d9c0d35b02880eec25fc3469d51d94738c075e14 Mon Sep 17 00:00:00 2001
From: Nicolas George <geo...@nsup.org>
Date: Thu, 4 Dec 2014 13:37:08 +0100
Subject: [PATCH 1/2] lavd/lavfi: allow to extract subcc.
Signed-off-by: Nicolas George <geo...@nsup.org>
---
doc/indevs.texi | 14 ++++++++
libavdevice/lavfi.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 99 insertions(+), 7 deletions(-)
diff --git a/doc/indevs.texi b/doc/indevs.texi
index ad823ab..abc4cc3 100644
--- a/doc/indevs.texi
+++ b/doc/indevs.texi
@@ -495,6 +495,14 @@ generated by the device.
The first unlabelled output is automatically assigned to the "out0"
label, but all the others need to be specified explicitly.
+The suffix "+subcc" can be appended to the output label to create an extra
+stream with the closed captions packets attached to that output
+(experimental; only for EIA-608 / CEA-708 for now).
+The subcc streams are created after all the normal streams, in the order of
+the corresponding stream.
+For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
+stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
+
If not specified defaults to the filename specified for the input
device.
@@ -541,6 +549,12 @@ Read an audio stream and a video stream and play it back with
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
@end example
+@item
+Dump decoded frames to images and closed captions to a file (experimental):
+@example
+ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
+@end example
+
@end itemize
@section libcdio
diff --git a/libavdevice/lavfi.c b/libavdevice/lavfi.c
index 1398ece..d0e6bf5 100644
--- a/libavdevice/lavfi.c
+++ b/libavdevice/lavfi.c
@@ -51,7 +51,10 @@ typedef struct {
int *sink_stream_map;
int *sink_eof;
int *stream_sink_map;
+ int *sink_stream_subcc_map;
AVFrame *decoded_frame;
+ int nb_sinks;
+ AVPacket subcc_packet;
} LavfiContext;
static int *create_all_formats(int n)
@@ -82,6 +85,7 @@ av_cold static int lavfi_read_close(AVFormatContext *avctx)
av_freep(&lavfi->sink_stream_map);
av_freep(&lavfi->sink_eof);
av_freep(&lavfi->stream_sink_map);
+ av_freep(&lavfi->sink_stream_subcc_map);
av_freep(&lavfi->sinks);
avfilter_graph_free(&lavfi->graph);
av_frame_free(&lavfi->decoded_frame);
@@ -89,6 +93,27 @@ av_cold static int lavfi_read_close(AVFormatContext *avctx)
return 0;
}
+static int create_subcc_streams(AVFormatContext *avctx)
+{
+ LavfiContext *lavfi = avctx->priv_data;
+ AVStream *st;
+ int stream_idx, sink_idx;
+
+ for (stream_idx = 0; stream_idx < lavfi->nb_sinks; stream_idx++) {
+ sink_idx = lavfi->stream_sink_map[stream_idx];
+ if (lavfi->sink_stream_subcc_map[sink_idx]) {
+ lavfi->sink_stream_subcc_map[sink_idx] = avctx->nb_streams;
+ if (!(st = avformat_new_stream(avctx, NULL)))
+ return AVERROR(ENOMEM);
+ st->codec->codec_id = AV_CODEC_ID_EIA_608;
+ st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
+ } else {
+ lavfi->sink_stream_subcc_map[sink_idx] = -1;
+ }
+ }
+ return 0;
+}
+
av_cold static int lavfi_read_header(AVFormatContext *avctx)
{
LavfiContext *lavfi = avctx->priv_data;
@@ -153,6 +178,7 @@ av_cold static int lavfi_read_header(AVFormatContext *avctx)
/* count the outputs */
for (n = 0, inout = output_links; inout; n++, inout = inout->next);
+ lavfi->nb_sinks = n;
if (!(lavfi->sink_stream_map = av_malloc(sizeof(int) * n)))
FAIL(AVERROR(ENOMEM));
@@ -160,6 +186,8 @@ av_cold static int lavfi_read_header(AVFormatContext *avctx)
FAIL(AVERROR(ENOMEM));
if (!(lavfi->stream_sink_map = av_malloc(sizeof(int) * n)))
FAIL(AVERROR(ENOMEM));
+ if (!(lavfi->sink_stream_subcc_map = av_malloc(sizeof(int) * n)))
+ FAIL(AVERROR(ENOMEM));
for (i = 0; i < n; i++)
lavfi->stream_sink_map[i] = -1;
@@ -167,14 +195,22 @@ av_cold static int lavfi_read_header(AVFormatContext *avctx)
/* parse the output link names - they need to be of the form out0, out1, ...
* create a mapping between them and the streams */
for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
- int stream_idx;
- if (!strcmp(inout->name, "out"))
- stream_idx = 0;
- else if (sscanf(inout->name, "out%d\n", &stream_idx) != 1) {
+ int stream_idx = 0, suffix = 0, use_subcc = 0;
+ sscanf(inout->name, "out%n%d%n", &suffix, &stream_idx, &suffix);
+ if (!suffix) {
av_log(avctx, AV_LOG_ERROR,
"Invalid outpad name '%s'\n", inout->name);
FAIL(AVERROR(EINVAL));
}
+ if (inout->name[suffix]) {
+ if (!strcmp(inout->name + suffix, "+subcc")) {
+ use_subcc = 1;
+ } else {
+ av_log(avctx, AV_LOG_ERROR,
+ "Invalid outpad suffix '%s'\n", inout->name);
+ FAIL(AVERROR(EINVAL));
+ }
+ }
if ((unsigned)stream_idx >= n) {
av_log(avctx, AV_LOG_ERROR,
@@ -192,6 +228,7 @@ av_cold static int lavfi_read_header(AVFormatContext *avctx)
}
lavfi->sink_stream_map[i] = stream_idx;
lavfi->stream_sink_map[stream_idx] = i;
+ lavfi->sink_stream_subcc_map[i] = !!use_subcc;
}
/* for each open output create a corresponding stream */
@@ -203,7 +240,7 @@ av_cold static int lavfi_read_header(AVFormatContext *avctx)
}
/* create a sink for each output and connect them to the graph */
- lavfi->sinks = av_malloc_array(avctx->nb_streams, sizeof(AVFilterContext *));
+ lavfi->sinks = av_malloc_array(lavfi->nb_sinks, sizeof(AVFilterContext *));
if (!lavfi->sinks)
FAIL(AVERROR(ENOMEM));
@@ -267,7 +304,7 @@ av_cold static int lavfi_read_header(AVFormatContext *avctx)
}
/* fill each stream with the information in the corresponding sink */
- for (i = 0; i < avctx->nb_streams; i++) {
+ for (i = 0; i < lavfi->nb_sinks; i++) {
AVFilterLink *link = lavfi->sinks[lavfi->stream_sink_map[i]]->inputs[0];
AVStream *st = avctx->streams[i];
st->codec->codec_type = link->type;
@@ -298,6 +335,9 @@ av_cold static int lavfi_read_header(AVFormatContext *avctx)
}
}
+ if ((ret = create_subcc_streams(avctx)) < 0)
+ FAIL(ret);
+
if (!(lavfi->decoded_frame = av_frame_alloc()))
FAIL(AVERROR(ENOMEM));
@@ -310,6 +350,30 @@ end:
return ret;
}
+static int create_subcc_packet(AVFormatContext *avctx, AVFrame *frame,
+ int sink_idx)
+{
+ LavfiContext *lavfi = avctx->priv_data;
+ AVFrameSideData *sd;
+ int stream_idx, i, ret;
+
+ if ((stream_idx = lavfi->sink_stream_subcc_map[sink_idx]) < 0)
+ return 0;
+ for (i = 0; i < frame->nb_side_data; i++)
+ if (frame->side_data[i]->type == AV_FRAME_DATA_A53_CC)
+ break;
+ if (i >= frame->nb_side_data)
+ return 0;
+ sd = frame->side_data[i];
+ if ((ret = av_new_packet(&lavfi->subcc_packet, sd->size)) < 0)
+ return ret;
+ memcpy(lavfi->subcc_packet.data, sd->data, sd->size);
+ lavfi->subcc_packet.stream_index = stream_idx;
+ lavfi->subcc_packet.pts = frame->pts;
+ lavfi->subcc_packet.pos = av_frame_get_pkt_pos(frame);
+ return 0;
+}
+
static int lavfi_read_packet(AVFormatContext *avctx, AVPacket *pkt)
{
LavfiContext *lavfi = avctx->priv_data;
@@ -321,9 +385,17 @@ static int lavfi_read_packet(AVFormatContext *avctx, AVPacket *pkt)
int ret, i;
int size = 0;
+ if (lavfi->subcc_packet.size) {
+ *pkt = lavfi->subcc_packet;
+ av_init_packet(&lavfi->subcc_packet);
+ lavfi->subcc_packet.size = 0;
+ lavfi->subcc_packet.data = NULL;
+ return pkt->size;
+ }
+
/* iterate through all the graph sinks. Select the sink with the
* minimum PTS */
- for (i = 0; i < avctx->nb_streams; i++) {
+ for (i = 0; i < lavfi->nb_sinks; i++) {
AVRational tb = lavfi->sinks[i]->inputs[0]->time_base;
double d;
int ret;
@@ -397,6 +469,12 @@ static int lavfi_read_packet(AVFormatContext *avctx, AVPacket *pkt)
av_bprint_finalize(&meta_buf, NULL);
}
+ if ((ret = create_subcc_packet(avctx, frame, min_pts_sink_idx)) < 0) {
+ av_frame_unref(frame);
+ av_packet_unref(pkt);
+ return ret;
+ }
+
pkt->stream_index = stream_idx;
pkt->pts = frame->pts;
pkt->pos = av_frame_get_pkt_pos(frame);
--
1.8.1.4
>From f6a382d43da4a72f2573bebc728d442bcc4c8c2c Mon Sep 17 00:00:00 2001
From: Anshul Maheshwari <anshul.ffm...@gmail.com>
Date: Wed, 31 Dec 2014 18:59:33 +0530
Subject: [PATCH 2/2] Adding Closed Caption Decoder
Signed-off-by: Anshul Maheshwari <anshul.ffm...@gmail.com>
For testing Closed caption following is the cmd
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map s some.srt
---
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/ccaption_dec.c | 349 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 351 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..37fcd70
--- /dev/null
+++ b/libavcodec/ccaption_dec.c
@@ -0,0 +1,349 @@
+/*
+ * 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"
+
+#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];
+}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);
+
+ return ret;
+}
+
+static av_cold int close_decoder(AVCodecContext *avctx)
+{
+ CCaptionSubContext *ctx = avctx->priv_data;
+ av_bprint_finalize( &ctx->buffer, NULL);
+ 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 uint8_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;
+
+ av_log(ctx, AV_LOG_DEBUG, "screen (handle edm)(%d)\n", ctx->active_screen);
+ ctx->start_time = ctx->startv_time;
+ for( i = 0; ctx->screen[1].row_used && i < SCREEN_ROWS; i++) {
+ if(CHECK_FLAG(ctx->screen[1].row_used, i)) {
+ av_log(ctx, AV_LOG_DEBUG,"screen inactive: (handle edm)(%s)\n",ctx->screen[1].characters[i]);
+ }
+ }
+ for( i = 0; screen->row_used && i < SCREEN_ROWS; i++)
+ {
+ if(CHECK_FLAG(screen->row_used,i)) {
+ av_log(ctx, AV_LOG_DEBUG,"screen (handle edm)(%s)\n",screen->characters[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;
+ }
+ }
+
+ }
+ av_log(ctx, AV_LOG_DEBUG,"cdp (handle edm)(%s)\n",ctx->buffer.str);
+ 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);
+ av_log(ctx, AV_LOG_DEBUG,"cdp (handle eoc)\n");
+ 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;
+ av_log(ctx, AV_LOG_DEBUG,"(%c,%c)\n",hi,lo);
+}
+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;
+ 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);
+ 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
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