[FFmpeg-devel] [PATCH] exr: zip1 decompression
Paul B Mahol
onemda at gmail.com
Wed Jul 11 01:26:07 CEST 2012
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
configure | 1 +
libavcodec/exr.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++------
2 files changed, 88 insertions(+), 11 deletions(-)
diff --git a/configure b/configure
index 1958fa6..8411836 100755
--- a/configure
+++ b/configure
@@ -1467,6 +1467,7 @@ eac3_encoder_select="mdct ac3dsp"
eamad_decoder_select="aandct"
eatgq_decoder_select="aandct"
eatqi_decoder_select="aandct"
+exr_decoder_select="zlib"
ffv1_decoder_select="golomb"
flac_decoder_select="golomb"
flac_encoder_select="golomb lpc"
diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 2a91722..ee82d77 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -30,6 +30,8 @@
* exr_flt2uint() and exr_halflt2uint() is credited to Reimar Döffinger
*/
+#include <zlib.h>
+
#include "avcodec.h"
#include "bytestream.h"
#include "libavutil/imgutils.h"
@@ -48,6 +50,12 @@ typedef struct EXRContext {
int compr;
int bits_per_color_id;
int8_t channel_offsets[4]; // 0 = red, 1 = green, 2 = blue and 3 = alpha
+
+ uint8_t *uncompressed_data;
+ int uncompressed_data_size;
+
+ uint8_t *tmp;
+ int tmp_size;;
} EXRContext;
/**
@@ -142,6 +150,38 @@ static int check_header_variable(AVCodecContext *avctx,
return -1;
}
+static void predictor(uint8_t *src, int size)
+{
+ uint8_t *t = src + 1;
+ uint8_t *stop = src + size;
+
+ while (t < stop) {
+ int d = (int)t[-1] + (int)t[0] - 128;
+ t[0] = d;
+ ++t;
+ }
+}
+
+static void reorder_data(uint8_t *src, uint8_t *dst, int size)
+{
+ const int8_t *t1 = src;
+ const int8_t *t2 = src + (size + 1) / 2;
+ int8_t *s = dst;
+ int8_t *stop = s + size;
+
+ while (1) {
+ if (s < stop)
+ *(s++) = *(t1++);
+ else
+ break;
+
+ if (s < stop)
+ *(s++) = *(t2++);
+ else
+ break;
+ }
+}
+
static int decode_frame(AVCodecContext *avctx,
void *data,
int *data_size,
@@ -165,6 +205,8 @@ static int decode_frame(AVCodecContext *avctx,
unsigned int ymax = ~0;
unsigned int xdelta = ~0;
+ unsigned long uncompressed_data_size;
+
unsigned int current_channel_offset = 0;
s->channel_offsets[0] = -1;
@@ -319,10 +361,10 @@ static int decode_frame(AVCodecContext *avctx,
s->compr = *buf;
switch (s->compr) {
case EXR_RAW:
- break;
- case EXR_RLE:
case EXR_ZIP1:
+ break;
case EXR_ZIP16:
+ case EXR_RLE:
case EXR_PIZ:
case EXR_B44:
default:
@@ -382,6 +424,8 @@ static int decode_frame(AVCodecContext *avctx,
return AVERROR_INVALIDDATA;
}
+ uncompressed_data_size = xdelta * av_pix_fmt_descriptors[avctx->pix_fmt].nb_components * FFMAX(2 * s->bits_per_color_id, 1);
+
if (s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
if (av_image_check_size(w, h, 0, avctx))
@@ -412,25 +456,53 @@ static int decode_frame(AVCodecContext *avctx,
}
// Process the actual lines
- for (y = ymin; y <= ymax; y++) {
+ for (y = ymin; y <= ymax; y++, ptr += stride) {
uint16_t *ptr_x = (uint16_t *)ptr;
if (buf_end - buf > 8) {
/* Read the lineoffset from the line offset table and add 8 bytes
to skip the coordinates and data size fields */
const uint64_t line_offset = bytestream_get_le64(&buf) + 8;
+ int32_t data_size;
+
// Check if the buffer has the required bytes needed from the offset
- if (line_offset > avpkt->size - xdelta * current_channel_offset) {
+ if ((line_offset > buf_size) ||
+ (s->compr == EXR_RAW && line_offset > avpkt->size - xdelta * current_channel_offset) ||
+ (s->compr != EXR_RAW && line_offset > buf_size - (data_size = AV_RL32(avpkt->data + line_offset - 4)))) {
// Line offset is probably wrong and not inside the buffer
av_log(avctx, AV_LOG_WARNING, "Line offset for line %d is out of reach setting it to black\n", y);
memset(ptr_x, 0, avctx->width * 2 * av_pix_fmt_descriptors[avctx->pix_fmt].nb_components);
} else {
- const uint8_t *red_channel_buffer = avpkt->data + line_offset + xdelta * s->channel_offsets[0];
- const uint8_t *green_channel_buffer = avpkt->data + line_offset + xdelta * s->channel_offsets[1];
- const uint8_t *blue_channel_buffer = avpkt->data + line_offset + xdelta * s->channel_offsets[2];
+ const uint8_t *red_channel_buffer;
+ const uint8_t *green_channel_buffer;
+ const uint8_t *blue_channel_buffer;
const uint8_t *alpha_channel_buffer = 0;
- if (s->channel_offsets[3] >= 0)
- alpha_channel_buffer = avpkt->data + line_offset + xdelta * s->channel_offsets[3];
+ if (s->compr == EXR_ZIP1 && data_size < uncompressed_data_size) {
+ av_fast_padded_malloc(&s->uncompressed_data, &s->uncompressed_data_size, uncompressed_data_size);
+ av_fast_padded_malloc(&s->tmp, &s->tmp_size, uncompressed_data_size);
+ if (!s->uncompressed_data || !s->tmp)
+ return AVERROR(ENOMEM);
+
+ if (uncompress(s->tmp, &uncompressed_data_size, avpkt->data + line_offset, data_size) != Z_OK) {
+ av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
+ return AVERROR(EINVAL);
+ }
+
+ predictor(s->tmp, uncompressed_data_size);
+ reorder_data(s->tmp, s->uncompressed_data, uncompressed_data_size);
+
+ red_channel_buffer = s->uncompressed_data + xdelta * s->channel_offsets[0];
+ green_channel_buffer = s->uncompressed_data + xdelta * s->channel_offsets[1];
+ blue_channel_buffer = s->uncompressed_data + xdelta * s->channel_offsets[2];
+ if (s->channel_offsets[3] >= 0)
+ alpha_channel_buffer = s->uncompressed_data + xdelta * s->channel_offsets[3];
+ } else {
+ red_channel_buffer = avpkt->data + line_offset + xdelta * s->channel_offsets[0];
+ green_channel_buffer = avpkt->data + line_offset + xdelta * s->channel_offsets[1];
+ blue_channel_buffer = avpkt->data + line_offset + xdelta * s->channel_offsets[2];
+ if (s->channel_offsets[3] >= 0)
+ alpha_channel_buffer = avpkt->data + line_offset + xdelta * s->channel_offsets[3];
+ }
// Zero out the start if xmin is not 0
memset(ptr_x, 0, xmin * 2 * av_pix_fmt_descriptors[avctx->pix_fmt].nb_components);
@@ -460,8 +532,6 @@ static int decode_frame(AVCodecContext *avctx,
ptr_x += (avctx->width - (xmax + 1)) * av_pix_fmt_descriptors[avctx->pix_fmt].nb_components;
}
- // Move to next line
- ptr += stride;
}
}
@@ -480,17 +550,23 @@ static int decode_frame(AVCodecContext *avctx,
static av_cold int decode_init(AVCodecContext *avctx)
{
EXRContext *s = avctx->priv_data;
+
avcodec_get_frame_defaults(&s->picture);
avctx->coded_frame = &s->picture;
+
return 0;
}
static av_cold int decode_end(AVCodecContext *avctx)
{
EXRContext *s = avctx->priv_data;
+
if (s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
+ av_freep(&s->uncompressed_data);
+ av_freep(&s->tmp);
+
return 0;
}
--
1.7.7
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