From: Gautam Ramakrishnan <gautamr...@gmail.com>
---
libavcodec/jpeg2000dec.c | 48 ++++++++++++++++++++++++++++++++++------
1 file changed, 41 insertions(+), 7 deletions(-)
diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 7103cd6ceb..9d52969821 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -83,6 +83,10 @@ typedef struct Jpeg2000Tile {
Jpeg2000QuantStyle qntsty[4];
Jpeg2000POC poc;
Jpeg2000TilePart tile_part[32];
+ uint8_t has_ppt; // whether this tile has a ppt
marker
+ uint8_t *packed_headers; // contains packed headers.
Used only along with PPT marker
+ int packed_headers_size; // size in bytes of the packed
headers
+ GetByteContext packed_headers_stream; // byte context corresponding
to packed headers
uint16_t tp_idx; // Tile-part index
int coord[2][2]; // border coordinates {{x0, x1}, {y0,
y1}}
} Jpeg2000Tile;
@@ -935,21 +939,32 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext
*s, Jpeg2000Tile *tile,
int bandno, cblkno, ret, nb_code_blocks;
int cwsno;
+// This part decodes the packet header
+
if (layno < rlevel->band[0].prec[precno].decoded_layers)
return 0;
rlevel->band[0].prec[precno].decoded_layers = layno + 1;
-
- if (bytestream2_get_bytes_left(&s->g) == 0 && s->bit_index == 8) {
- if (*tp_index < FF_ARRAY_ELEMS(tile->tile_part) - 1) {
- s->g = tile->tile_part[++(*tp_index)].tpg;
+ // Select appropriate stream to read from
+ if (tile->has_ppt) {
+ s->g = tile->packed_headers_stream;
+ } else {
+ s->g = tile->tile_part[*tp_index].tpg;
+ if (bytestream2_get_bytes_left(&s->g) == 0 && s->bit_index == 8) {
+ if (*tp_index < FF_ARRAY_ELEMS(tile->tile_part) - 1) {
+ s->g = tile->tile_part[++(*tp_index)].tpg;
+ }
}
+ if (bytestream2_peek_be32(&s->g) == JPEG2000_SOP_FIXED_BYTES)
+ bytestream2_skip(&s->g, JPEG2000_SOP_BYTE_LENGTH);
}
- if (bytestream2_peek_be32(&s->g) == JPEG2000_SOP_FIXED_BYTES)
- bytestream2_skip(&s->g, JPEG2000_SOP_BYTE_LENGTH);
-
if (!(ret = get_bits(s, 1))) {
jpeg2000_flush(s);
+ // Save state of stream
+ if (tile->has_ppt)
+ tile->packed_headers_stream = s->g;
+ else
+ tile->tile_part[*tp_index].tpg = s->g;
return 0;
} else if (ret < 0)
return ret;
@@ -1056,6 +1071,23 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext
*s, Jpeg2000Tile *tile,
av_log(s->avctx, AV_LOG_ERROR, "EPH marker not found. instead
%X\n", bytestream2_peek_be32(&s->g));
}
+ if (tile->has_ppt)
+ tile->packed_headers_stream = s->g;
+ else
+ tile->tile_part[*tp_index].tpg = s->g;
+
+// This part decodes the packet data.
+ // Select appropriate stream to read from
+ s->g = tile->tile_part[*tp_index].tpg;
+ if (tile->has_ppt) {
+ if (bytestream2_get_bytes_left(&s->g) == 0 && s->bit_index == 8) {
+ if (*tp_index < FF_ARRAY_ELEMS(tile->tile_part) - 1) {
+ s->g = tile->tile_part[++(*tp_index)].tpg;
+ }
+ }
+ if (bytestream2_peek_be32(&s->g) == JPEG2000_SOP_FIXED_BYTES)
+ bytestream2_skip(&s->g, JPEG2000_SOP_BYTE_LENGTH);
+ }
for (bandno = 0; bandno < rlevel->nbands; bandno++) {
Jpeg2000Band *band = rlevel->band + bandno;
Jpeg2000Prec *prec = band->prec + precno;
@@ -1097,6 +1129,8 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext
*s, Jpeg2000Tile *tile,
av_freep(&cblk->lengthinc);
}
}
+ // Save state of stream
+ tile->tile_part[*tp_index].tpg = s->g;
return 0;
}
--
2.17.1
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