From: Gautam Ramakrishnan
This patch adds functional changes to support the
PPT marker.
---
libavcodec/jpeg2000dec.c | 88 +++-
1 file changed, 77 insertions(+), 11 deletions(-)
diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 7103cd6ceb..01509d62c1 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -83,6 +83,10 @@ typedef struct Jpeg2000Tile {
Jpeg2000QuantStyle qntsty[4];
Jpeg2000POC poc;
Jpeg2000TileParttile_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;
@@ -855,6 +859,37 @@ static int get_plt(Jpeg2000DecoderContext *s, int n)
return 0;
}
+static int get_ppt(Jpeg2000DecoderContext *s, int n)
+{
+Jpeg2000Tile *tile;
+
+if (s->curtileno < 0)
+return AVERROR_INVALIDDATA;
+
+tile = >tile[s->curtileno];
+if (tile->tp_idx != 0) {
+av_log(s->avctx, AV_LOG_ERROR,
+ "PPT marker can occur only on first tile part of a tile.\n");
+return AVERROR_INVALIDDATA;
+}
+
+tile->has_ppt = 1; // this tile has a ppt marker
+/*Zppt = */ bytestream2_get_byte(>g); // Zppt is skipped and not used
+if (!tile->packed_headers)
+tile->packed_headers = av_malloc(n - 3);
+else
+tile->packed_headers = av_realloc(tile->packed_headers,
+ tile->packed_headers_size + n - 3);
+if (!tile->packed_headers)
+return AVERROR(ENOMEM);
+memcpy(tile->packed_headers + tile->packed_headers_size,
+ s->g.buffer, n - 3);
+tile->packed_headers_size += n - 3;
+bytestream2_skip(>g, n - 3);
+
+return 0;
+}
+
static int init_tile(Jpeg2000DecoderContext *s, int tileno)
{
int compno;
@@ -927,6 +962,19 @@ static int getlblockinc(Jpeg2000DecoderContext *s)
return res;
}
+static inline void select_stream(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
+ int *tp_index)
+{
+s->g = tile->tile_part[*tp_index].tpg;
+if (bytestream2_get_bytes_left(>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(>g) == JPEG2000_SOP_FIXED_BYTES)
+bytestream2_skip(>g, JPEG2000_SOP_BYTE_LENGTH);
+}
+
static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Tile
*tile, int *tp_index,
Jpeg2000CodingStyle *codsty,
Jpeg2000ResLevel *rlevel, int precno,
@@ -938,19 +986,15 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext
*s, Jpeg2000Tile *tile,
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(>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(>g) == JPEG2000_SOP_FIXED_BYTES)
-bytestream2_skip(>g, JPEG2000_SOP_BYTE_LENGTH);
+// Select stream to read from
+if (tile->has_ppt)
+s->g = tile->packed_headers_stream;
+else
+select_stream(s, tile, tp_index);
if (!(ret = get_bits(s, 1))) {
jpeg2000_flush(s);
-return 0;
+goto skip_data;
} else if (ret < 0)
return ret;
@@ -1056,6 +1100,11 @@ 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(>g));
}
+// Save state of stream
+if (tile->has_ppt) {
+tile->packed_headers_stream = s->g;
+select_stream(s, tile, tp_index);
+}
for (bandno = 0; bandno < rlevel->nbands; bandno++) {
Jpeg2000Band *band = rlevel->band + bandno;
Jpeg2000Prec *prec = band->prec + precno;
@@ -1097,6 +1146,15 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext
*s, Jpeg2000Tile *tile,
av_freep(>lengthinc);
}
}
+// Save state of stream
+tile->tile_part[*tp_index].tpg = s->g;
+return 0;
+
+skip_data:
+if (tile->has_ppt)
+tile->packed_headers_stream = s->g;
+else
+tile->tile_part[*tp_index].tpg = s->g;
return 0;
}
@@ -1929,6 +1987,11 @@ static int
