[FFmpeg-devel] [PATCH v3 1/2] lavc/ccaption_dec: do not ignore repeated character commands
Aman Gupta
aman at tmm1.net
Mon Apr 18 22:01:44 CEST 2016
Please send me the sample and I will try to fix the issue.
Aman
On Mon, Apr 18, 2016 at 1:22 PM Thierry Foucu <tfoucu at gmail.com> wrote:
> Hi all
>
> On Sun, Feb 14, 2016 at 6:11 PM, Aman Gupta <ffmpeg at tmm1.net> wrote:
>
>> From: Aman Gupta <aman at tmm1.net>
>>
>> control codes in a cc stream can be repeated, and must be ignored.
>> however, repeated characters must not be ignored. the code attempted to
>> wipe prev_cmd in handle_char to allow repeated characters to be
>> processed, but prev_cmd would previously get reset _after_ handle_char()
>>
>> i also moved the prev_cmd reset out from handle_char() so it can be
>> re-used for special character sets, which _must_ be ignored when
>> repeated.
>> ---
>> libavcodec/ccaption_dec.c | 19 ++++++++++---------
>> 1 file changed, 10 insertions(+), 9 deletions(-)
>>
>> diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
>> index 790f071..5fb2ec6 100644
>> --- a/libavcodec/ccaption_dec.c
>> +++ b/libavcodec/ccaption_dec.c
>> @@ -484,9 +484,6 @@ static void handle_char(CCaptionSubContext *ctx, char
>> hi, char lo, int64_t pts)
>> if (ctx->mode != CCMODE_POPON)
>> ctx->screen_touched = 1;
>>
>> - /* reset prev command since character can repeat */
>> - ctx->prev_cmd[0] = 0;
>> - ctx->prev_cmd[1] = 0;
>> if (lo)
>> ff_dlog(ctx, "(%c,%c)\n", hi, lo);
>> else
>> @@ -497,8 +494,15 @@ static void process_cc608(CCaptionSubContext *ctx,
>> int64_t pts, uint8_t hi, uint
>> {
>> 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)
>> ) ) {
>> + return;
>> + }
>> +
>> + /* set prev command */
>> + ctx->prev_cmd[0] = hi;
>> + ctx->prev_cmd[1] = lo;
>> +
>> + 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) ) {
>> @@ -559,14 +563,11 @@ static void process_cc608(CCaptionSubContext *ctx,
>> int64_t pts, uint8_t hi, uint
>> } else if (hi >= 0x20) {
>> /* Standard characters (always in pairs) */
>> handle_char(ctx, hi, lo, pts);
>> + ctx->prev_cmd[0] = ctx->prev_cmd[1] = 0;
>> } else {
>> /* Ignoring all other non data code */
>> ff_dlog(ctx, "Unknown command 0x%hhx 0x%hhx\n", hi, lo);
>> }
>> -
>> - /* set prev command */
>> - ctx->prev_cmd[0] = hi;
>> - ctx->prev_cmd[1] = lo;
>> }
>>
>> static int decode(AVCodecContext *avctx, void *data, int *got_sub,
>> AVPacket *avpkt)
>> --
>> 2.5.3
>>
>>
> This commit seems to break some US broadcast CC decoding. (I can provide a
> 15MB sample file if needed)
>
> Before this commit:
> ffmpeg -f lavfi -i "movie=IhedxzUUxNo.ts[out0+subcc]" -map s "ts.srt"
> cat ts.srt
> 1
> 00:00:01,035 --> 00:00:02,035
> <font face="Monospace">FAR-RANGING IMPACT PLACES IN THE</font>
>
> 2
> 00:00:02,036 --> 00:00:04,466
> <font face="Monospace">FAR-RANGING IMPACT PLACES IN THE
> CHURCH AND AT THE LEVEL OF</font>
>
> 3
> 00:00:04,471 --> 00:00:06,811
> <font face="Monospace">CHURCH AND AT THE LEVEL OF
> POLICY ALL ACROSS THE GLOBE.</font>
>
> 4
> 00:00:06,807 --> 00:00:08,537
> <font face="Monospace">POLICY ALL ACROSS THE GLOBE.
> CERTAINLY IN THE AREA OF</font>
>
> 5
> 00:00:08,542 --> 00:00:10,382
> <font face="Monospace">CERTAINLY IN THE AREA OF
> PASTORAL CARE, I HOPE THAT IT</font>
>
> 6
> 00:00:10,377 --> 00:00:14,677
> <font face="Monospace">PASTORAL CARE, I HOPE THAT IT
> WILL LEAD TO LESS DOGMATICTI</font>
>
> 7
> 00:00:14,682 --> 00:00:16,352
> <font face="Monospace">WILL LEAD TO LESS DOGMATICTI
> INTERACTION WITH PEOPLE ACROSS A</font>
>
> 8
> 00:00:16,350 --> 00:00:16,920
> <font face="Monospace">INTERACTION WITH PEOPLE ACROSS A
> THE BOARD.</font>
>
> 9
> 00:00:16,917 --> 00:00:18,287
> <font face="Monospace">THE BOARD.
> I HOPE THAT, YOU KNOW, THERE'S</font>
>
> 10
> 00:00:18,285 --> 00:00:20,785
> <font face="Monospace">I HOPE THAT, YOU KNOW, THERE'S
> MORE OF A SENSE THAT THE CHURCH</font>
>
>
>
> After that commit,
> cat ts.srt
> 1
> 00:00:01,035 --> 00:00:02,035
> <font face="Monospace">FFFARARAR-R-R-RANANANGIGIGINGNGN</font>
>
> 2
> 00:00:02,036 --> 00:00:04,466
> <font face="Monospace">FFFARARAR-R-R-RANANANGIGIGINGNGN
> CCCHUHUHURCRCRCHHH A A ANNND D D</font>
>
> 3
> 00:00:04,471 --> 00:00:06,811
> <font face="Monospace">CCCHUHUHURCRCRCHHH A A ANNND D D
> POPOPOLILILICYCYCY A A ALLLL L L</font>
>
> 4
> 00:00:06,807 --> 00:00:08,537
> <font face="Monospace">POPOPOLILILICYCYCY A A ALLLL L L
> CCCERERERTATATAINININLYLYLY I I </font>
>
> 5
> 00:00:08,542 --> 00:00:10,382
> <font face="Monospace">CCCERERERTATATAINININLYLYLY I I
> PAPAPASSSTOTOTORARARALLL C C CAA</font>
>
> 6
> 00:00:10,377 --> 00:00:14,677
> <font face="Monospace">PAPAPASSSTOTOTORARARALLL C C CAA
> WIWIWILLLLLL LELELEADADAD TO</font>
>
> 7
> 00:00:14,682 --> 00:00:16,352
> <font face="Monospace">WIWIWILLLLLL LELELEADADAD TO
> INININTETETERARARACTCTCTIOIOION </font>
>
> 8
> 00:00:16,350 --> 00:00:16,920
> <font face="Monospace">INININTETETERARARACTCTCTIOIOION
> THTHTHE E E BOBOBOAAARDRDRD...</font>
>
> 9
> 00:00:16,917 --> 00:00:18,287
> <font face="Monospace">THTHTHE E E BOBOBOAAARDRDRD...
> I I I HHHOPOPOPEEE T T THHHATATA</font>
>
> 10
> 00:00:18,285 --> 00:00:20,785
> <font face="Monospace">I I I HHHOPOPOPEEE T T THHHATATA
> MOMOMORRRE E E OFOFOF A A A SE</font>
>
>
>
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>
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