From f9581f1414ec8e3e7d0868793cda4f2e4fa113ea Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 1 Jul 2013 10:01:20 +0200 Subject: [PATCH] jpeg2000: Improve reduced resolution decoding Correctly scale down the component coordinates and clean up some redundant code. Signed-off-by: Luca Barbato --- libavcodec/jpeg2000dec.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c index 9befa8b31d..47b07ebb67 100644 --- a/libavcodec/jpeg2000dec.c +++ b/libavcodec/jpeg2000dec.c @@ -84,8 +84,7 @@ typedef struct Jpeg2000DecoderContext { Jpeg2000Tile *tile; /*options parameters*/ - int16_t lowres; - int16_t reduction_factor; + int reduction_factor; } Jpeg2000DecoderContext; /* get_bits functions for JPEG2000 packet bitstream @@ -599,12 +598,10 @@ static int init_tile(Jpeg2000DecoderContext *s, int tileno) comp->coord_o[1][0] = FFMAX(tiley * s->tile_height + s->tile_offset_y, s->image_offset_y); comp->coord_o[1][1] = FFMIN((tiley + 1) * s->tile_height + s->tile_offset_y, s->height); - // FIXME: add a dcinema profile check ? - // value is guaranteed by profile (orig=0, 1 tile) - comp->coord[0][0] = 0; - comp->coord[0][1] = s->avctx->width; - comp->coord[1][0] = 0; - comp->coord[1][1] = s->avctx->height; + comp->coord[0][0] = ff_jpeg2000_ceildivpow2(comp->coord_o[0][0], s->reduction_factor); + comp->coord[0][1] = ff_jpeg2000_ceildivpow2(comp->coord_o[0][1], s->reduction_factor); + comp->coord[1][0] = ff_jpeg2000_ceildivpow2(comp->coord_o[1][0], s->reduction_factor); + comp->coord[1][1] = ff_jpeg2000_ceildivpow2(comp->coord_o[1][1], s->reduction_factor); if (ret = ff_jpeg2000_init_component(comp, codsty, qntsty, s->cbps[compno], s->cdx[compno], @@ -1351,9 +1348,6 @@ static int jpeg2000_decode_frame(AVCodecContext *avctx, void *data, bytestream2_init(&s->g, avpkt->data, avpkt->size); s->curtileno = 0; // TODO: only one tile in DCI JP2K. to implement for more tiles - // reduction factor, i.e number of resolution levels to skip - s->reduction_factor = s->lowres; - if (bytestream2_get_bytes_left(&s->g) < 2) return AVERROR_INVALIDDATA; @@ -1413,7 +1407,7 @@ static void jpeg2000_init_static_data(AVCodec *codec) static const AVOption options[] = { { "lowres", "Lower the decoding resolution by a power of two", - OFFSET(lowres), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, JPEG2000_MAX_RESLEVELS - 1, VD }, + OFFSET(reduction_factor), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, JPEG2000_MAX_RESLEVELS - 1, VD }, { NULL }, }; -- 2.11.0