[FFmpeg-devel] [PATCH] JPEG2000 encoding with variable codeblock size

Francesco, Cuzzocrea francesco at bltitalia.com
Fri Aug 4 19:23:36 EEST 2017


Sorry..... I intend 32x128....


On 04/08/2017 10.21, Francesco, Cuzzocrea wrote:
> The standard ISO/IEC FCD15444-1 specify limits for the exponent values 
> and their sum. That is codeblock
>
> size xcb and ycb are defined as:
>
> xcb = 2^(xvalue+2)  and ycb = 2^(yvalue+2)
>
> with values that ranges from a minimum of 2 and a maximum of 10. Moreover
>
> the sum should be less or equal to 12 ( xvalue + yvalue <=12). So 
> 64x128 are allowed because
>
> xvalue = 4 and yvalue = 5.
>
>
>
> On 03/08/2017 19.24, Aaron Boxer wrote:
>> On Aug 3, 2017 9:58 AM, <francesco at bltitalia.com> wrote:
>>
>> From: Francesco Cuzzocrea <francesco at bltitalia.com>
>>
>> Hi to all
>> I've made some simple changes tha allow encoding with variable codeblock
>> size.  Default value are the same as previous (16X16) but now setting 
>> them
>> to 64x128 make generated codestream compatible with Analog Devices 
>> ADV212
>> video codec.
>>
>>
>> Interesting - as far as I  aware, part 1 of standard only allows 
>> codeblock
>> of max size 4096, so 64x128 would not be legal.
>>
>>
>>
>> ---
>>   libavcodec/j2kenc.c | 22 +++++++++++++---------
>>   1 file changed, 13 insertions(+), 9 deletions(-)
>>
>> diff --git a/libavcodec/j2kenc.c b/libavcodec/j2kenc.c
>> index c8d3861..1bd4fbd 100644
>> --- a/libavcodec/j2kenc.c
>> +++ b/libavcodec/j2kenc.c
>> @@ -1178,17 +1178,21 @@ static int j2kenc_destroy(AVCodecContext *avctx)
>>   // taken from the libopenjpeg wraper so it matches
>>
>>   #define OFFSET(x) offsetof(Jpeg2000EncoderContext, x)
>> +#define OFFSET1(x) offsetof(Jpeg2000CodingStyle, x)
>> +
>> +
>>   #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
>>   static const AVOption options[] = {
>> -    { "format",        "Codec Format",      OFFSET(format),
>> AV_OPT_TYPE_INT,   { .i64 = CODEC_JP2   }, CODEC_J2K, CODEC_JP2,   VE,
>> "format"      },
>> -    { "j2k",           NULL,                0,
>>   AV_OPT_TYPE_CONST, { .i64 = CODEC_J2K   }, 0, 0,           VE,
>> "format"      },
>> -    { "jp2",           NULL,                0,
>>   AV_OPT_TYPE_CONST, { .i64 = CODEC_JP2   }, 0, 0,           VE,
>> "format"      },
>> -    { "tile_width",    "Tile Width",        OFFSET(tile_width),
>> AV_OPT_TYPE_INT,   { .i64 = 256         }, 1, 1<<30,           VE, },
>> -    { "tile_height",   "Tile Height", OFFSET(tile_height),
>>   AV_OPT_TYPE_INT,   { .i64 = 256         }, 1, 1<<30,           VE, },
>> -    { "pred",          "DWT Type",          OFFSET(pred),
>> AV_OPT_TYPE_INT,   { .i64 = 0           }, 0, 1,           VE,
>> "pred"        },
>> -    { "dwt97int",      NULL,                0,
>>   AV_OPT_TYPE_CONST, { .i64 = 0           }, INT_MIN, INT_MAX,       VE,
>> "pred"        },
>> -    { "dwt53",         NULL,                0,
>>   AV_OPT_TYPE_CONST, { .i64 = 0           }, INT_MIN, INT_MAX,       VE,
>> "pred"        },
>> -
>> +    { "format",           "Codec Format",       OFFSET(format),
>>                     AV_OPT_TYPE_INT,   { .i64 = CODEC_JP2   }, 
>> CODEC_J2K,
>> CODEC_JP2,   VE, "format"      },
>> +    { "j2k",               NULL,                0,
>>                      AV_OPT_TYPE_CONST, { .i64 = CODEC_J2K   }, 0,
>>   0,           VE, "format"      },
>> +    { "jp2",               NULL,                0,
>>                      AV_OPT_TYPE_CONST, { .i64 = CODEC_JP2   }, 0,
>>   0,           VE, "format"      },
>> +    { "tile_width",        "Tile Width", OFFSET(tile_width),
>>                     AV_OPT_TYPE_INT,   { .i64 = 256         }, 1,
>>   1<<30,           VE, },
>> +    { "tile_height",       "Tile Height", OFFSET(tile_height),
>>                      AV_OPT_TYPE_INT,   { .i64 = 256         }, 1,
>>   1<<30,           VE, },
>> +    { "pred",              "DWT Type",          OFFSET(pred),
>>                     AV_OPT_TYPE_INT,   { .i64 = 0           }, 0,
>>   1,           VE, "pred"        },
>> +    { "dwt97int",          NULL,                0,
>>                      AV_OPT_TYPE_CONST, { .i64 = 0           }, INT_MIN,
>> INT_MAX,       VE, "pred"        },
>> +    { "dwt53",             NULL,                0,
>>                      AV_OPT_TYPE_CONST, { .i64 = 0           }, INT_MIN,
>> INT_MAX,       VE, "pred"        },
>> +    { "log2_cblk_width",   "Codeblock Width",
>>   (OFFSET(codsty)+OFFSET1(log2_cblk_width)), AV_OPT_TYPE_INT,   { .i64 =
>> 4           }, 1,     1<<30,           VE, },
>> +    { "log2_cblk_height",  "Codeblock Height",
>> (OFFSET(codsty)+OFFSET1(log2_cblk_height)),   AV_OPT_TYPE_INT, { .i64 =
>> 4           }, 1,     1<<30,           VE, },
>>       { NULL }
>>   };
>>
>> -- 
>> 2.1.4
>>
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>

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*    Ing. Francesco  Cuzzocrea
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