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j2kdec: merge get_tlm() from jpeg2000

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Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2013-05-28 01:10:26 +02:00
parent 8cf57efdd7
commit d66de3801e
1 changed files with 46 additions and 0 deletions
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46
libavcodec/j2kdec.c
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@ -432,6 +432,48 @@ static int get_sot(Jpeg2000DecoderContext *s)
return 0;
}
/* Tile-part lengths: see ISO 15444-1:2002, section A.7.1
* Used to know the number of tile parts and lengths.
* There may be multiple TLMs in the header.
* TODO: The function is not used for tile-parts management, nor anywhere else.
* It can be useful to allocate memory for tile parts, before managing the SOT
* markers. Parsing the TLM header is needed to increment the input header
* buffer.
* This marker is mandatory for DCI. */
static uint8_t get_tlm(Jpeg2000DecoderContext *s, int n)
{
uint8_t Stlm, ST, SP, tile_tlm, i;
bytestream2_get_byte(&s->g); /* Ztlm: skipped */
Stlm = bytestream2_get_byte(&s->g);
// too complex ? ST = ((Stlm >> 4) & 0x01) + ((Stlm >> 4) & 0x02);
ST = (Stlm >> 4) & 0x03;
// TODO: Manage case of ST = 0b11 --> raise error
SP = (Stlm >> 6) & 0x01;
tile_tlm = (n - 4) / ((SP + 1) * 2 + ST);
for (i = 0; i < tile_tlm; i++) {
switch (ST) {
case 0:
break;
case 1:
bytestream2_get_byte(&s->g);
break;
case 2:
bytestream2_get_be16(&s->g);
break;
case 3:
bytestream2_get_be32(&s->g);
break;
}
if (SP == 0) {
bytestream2_get_be16(&s->g);
} else {
bytestream2_get_be32(&s->g);
}
}
return 0;
}
static int init_tile(Jpeg2000DecoderContext *s, int tileno)
{
int compno;
@ -994,6 +1036,10 @@ static int decode_codestream(Jpeg2000DecoderContext *s)
// the comment is ignored
bytestream2_skip(&s->g, len - 2);
break;
case JPEG2000_TLM:
// Tile-part lengths
ret = get_tlm(s, len);
break;
default:
av_log(s->avctx, AV_LOG_ERROR, "unsupported marker 0x%.4X at pos 0x%x\n", marker, bytestream2_tell(&s->g) - 4);
bytestream2_skip(&s->g, len - 2);