* RTJpeg decoding functions
* Copyright (c) 2006 Reimar Doeffinger
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/common.h"
i = scan[coeff--]; \
block[i] = (c) * quant[i];
-//! aligns the bitstream to the give power of two
+/// aligns the bitstream to the given power of two
#define ALIGN(a) \
n = (-get_bits_count(gb)) & (a - 1); \
if (n) {skip_bits(gb, n);}
/**
- * \brief read one block from stream
- * \param gb contains stream data
- * \param block where data is written to
- * \param scan array containing the mapping stream address -> block position
- * \param quant quantization factors
+ * @brief read one block from stream
+ * @param gb contains stream data
+ * @param block where data is written to
+ * @param scan array containing the mapping stream address -> block position
+ * @param quant quantization factors
+ * @return 0 means the block is not coded, < 0 means an error occurred.
*
* Note: GetBitContext is used to make the code simpler, since all data is
* aligned this could be done faster in a different way, e.g. as it is done
// number of non-zero coefficients
coeff = get_bits(gb, 6);
- if (get_bits_count(gb) + (coeff << 1) >= gb->size_in_bits)
- return 0;
+ if (get_bits_left(gb) < (coeff << 1))
+ return -1;
// normally we would only need to clear the (63 - coeff) last values,
// but since we do not know where they are we just clear the whole block
// 4 bits per coefficient
ALIGN(4);
- if (get_bits_count(gb) + (coeff << 2) >= gb->size_in_bits)
- return 0;
+ if (get_bits_left(gb) < (coeff << 2))
+ return -1;
while (coeff) {
ac = get_sbits(gb, 4);
if (ac == -8)
// 8 bits per coefficient
ALIGN(8);
- if (get_bits_count(gb) + (coeff << 3) >= gb->size_in_bits)
- return 0;
+ if (get_bits_left(gb) < (coeff << 3))
+ return -1;
while (coeff) {
ac = get_sbits(gb, 8);
PUT_COEFF(ac);
}
/**
- * \brief decode one rtjpeg YUV420 frame
- * \param c context, must be initialized via rtjpeg_decode_init
- * \param f AVFrame to place decoded frame into. If parts of the frame
+ * @brief decode one rtjpeg YUV420 frame
+ * @param c context, must be initialized via ff_rtjpeg_decode_init
+ * @param f AVFrame to place decoded frame into. If parts of the frame
* are not coded they are left unchanged, so consider initializing it
- * \param buf buffer containing input data
- * \param buf_size length of input data in bytes
- * \return number of bytes consumed from the input buffer
+ * @param buf buffer containing input data
+ * @param buf_size length of input data in bytes
+ * @return number of bytes consumed from the input buffer
*/
-int rtjpeg_decode_frame_yuv420(RTJpegContext *c, AVFrame *f,
- const uint8_t *buf, int buf_size) {
+int ff_rtjpeg_decode_frame_yuv420(RTJpegContext *c, AVFrame *f,
+ const uint8_t *buf, int buf_size) {
GetBitContext gb;
int w = c->w / 16, h = c->h / 16;
int x, y;
init_get_bits(&gb, buf, buf_size * 8);
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
+#define BLOCK(quant, dst, stride) do { \
+ int res = get_block(&gb, block, c->scan, quant); \
+ if (res < 0) \
+ return res; \
+ if (res > 0) \
+ c->dsp->idct_put(dst, stride, block); \
+} while (0)
DCTELEM *block = c->block;
- if (get_block(&gb, block, c->scan, c->lquant))
- c->dsp->idct_put(y1, f->linesize[0], block);
+ BLOCK(c->lquant, y1, f->linesize[0]);
y1 += 8;
- if (get_block(&gb, block, c->scan, c->lquant))
- c->dsp->idct_put(y1, f->linesize[0], block);
+ BLOCK(c->lquant, y1, f->linesize[0]);
y1 += 8;
- if (get_block(&gb, block, c->scan, c->lquant))
- c->dsp->idct_put(y2, f->linesize[0], block);
+ BLOCK(c->lquant, y2, f->linesize[0]);
y2 += 8;
- if (get_block(&gb, block, c->scan, c->lquant))
- c->dsp->idct_put(y2, f->linesize[0], block);
+ BLOCK(c->lquant, y2, f->linesize[0]);
y2 += 8;
- if (get_block(&gb, block, c->scan, c->cquant))
- c->dsp->idct_put(u, f->linesize[1], block);
+ BLOCK(c->cquant, u, f->linesize[1]);
u += 8;
- if (get_block(&gb, block, c->scan, c->cquant))
- c->dsp->idct_put(v, f->linesize[2], block);
+ BLOCK(c->cquant, v, f->linesize[2]);
v += 8;
}
y1 += 2 * 8 * (f->linesize[0] - w);
}
/**
- * \brief initialize an RTJpegContext, may be called multiple times
- * \param c context to initialize
- * \param dsp specifies the idct to use for decoding
- * \param width width of image, will be rounded down to the nearest multiple
+ * @brief initialize an RTJpegContext, may be called multiple times
+ * @param c context to initialize
+ * @param dsp specifies the idct to use for decoding
+ * @param width width of image, will be rounded down to the nearest multiple
* of 16 for decoding
- * \param height height of image, will be rounded down to the nearest multiple
+ * @param height height of image, will be rounded down to the nearest multiple
* of 16 for decoding
- * \param lquant luma quantization table to use
- * \param cquant chroma quantization table to use
+ * @param lquant luma quantization table to use
+ * @param cquant chroma quantization table to use
*/
-void rtjpeg_decode_init(RTJpegContext *c, DSPContext *dsp,
- int width, int height,
- const uint32_t *lquant, const uint32_t *cquant) {
+void ff_rtjpeg_decode_init(RTJpegContext *c, DSPContext *dsp,
+ int width, int height,
+ const uint32_t *lquant, const uint32_t *cquant) {
int i;
c->dsp = dsp;
for (i = 0; i < 64; i++) {
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