diff --git a/libavcodec/j2kdec.c b/libavcodec/j2kdec.c index 40afced32f..a9ad8c1b97 100644 --- a/libavcodec/j2kdec.c +++ b/libavcodec/j2kdec.c @@ -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);