rtjpeg: Convert to the new bitstream reader

pull/117/merge
Alexandra Hájková 9 years ago committed by Diego Biurrun
parent c60cda7cb4
commit f26cbb555b
  1. 42
      libavcodec/rtjpeg.c

@ -18,8 +18,10 @@
* 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"
#include "get_bits.h"
#include "bitstream.h"
#include "rtjpeg.h"
#define PUT_COEFF(c) \
@ -28,34 +30,36 @@
/// 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);}
n = (-bitstream_tell(bc)) & (a - 1); \
if (n) \
bitstream_skip(bc, n);
/**
* @brief read one block from stream
* @param gb contains stream data
* @param bc 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
* Note: BitstreamContext 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
* in MPlayer libmpcodecs/native/rtjpegn.c.
*/
static inline int get_block(GetBitContext *gb, int16_t *block, const uint8_t *scan,
const uint32_t *quant) {
static inline int get_block(BitstreamContext *bc, int16_t *block,
const uint8_t *scan, const uint32_t *quant)
{
int coeff, i, n;
int8_t ac;
uint8_t dc = get_bits(gb, 8);
uint8_t dc = bitstream_read(bc, 8);
// block not coded
if (dc == 255)
return 0;
// number of non-zero coefficients
coeff = get_bits(gb, 6);
if (get_bits_left(gb) < (coeff << 1))
coeff = bitstream_read(bc, 6);
if (bitstream_bits_left(bc) < (coeff << 1))
return AVERROR_INVALIDDATA;
// normally we would only need to clear the (63 - coeff) last values,
@ -64,7 +68,7 @@ static inline int get_block(GetBitContext *gb, int16_t *block, const uint8_t *sc
// 2 bits per coefficient
while (coeff) {
ac = get_sbits(gb, 2);
ac = bitstream_read_signed(bc, 2);
if (ac == -2)
break; // continue with more bits
PUT_COEFF(ac);
@ -72,10 +76,10 @@ static inline int get_block(GetBitContext *gb, int16_t *block, const uint8_t *sc
// 4 bits per coefficient
ALIGN(4);
if (get_bits_left(gb) < (coeff << 2))
if (bitstream_bits_left(bc) < (coeff << 2))
return AVERROR_INVALIDDATA;
while (coeff) {
ac = get_sbits(gb, 4);
ac = bitstream_read_signed(bc, 4);
if (ac == -8)
break; // continue with more bits
PUT_COEFF(ac);
@ -83,10 +87,10 @@ static inline int get_block(GetBitContext *gb, int16_t *block, const uint8_t *sc
// 8 bits per coefficient
ALIGN(8);
if (get_bits_left(gb) < (coeff << 3))
if (bitstream_bits_left(bc) < (coeff << 3))
return AVERROR_INVALIDDATA;
while (coeff) {
ac = get_sbits(gb, 8);
ac = bitstream_read_signed(bc, 8);
PUT_COEFF(ac);
}
@ -105,19 +109,19 @@ static inline int get_block(GetBitContext *gb, int16_t *block, const uint8_t *sc
*/
int ff_rtjpeg_decode_frame_yuv420(RTJpegContext *c, AVFrame *f,
const uint8_t *buf, int buf_size) {
GetBitContext gb;
BitstreamContext bc;
int w = c->w / 16, h = c->h / 16;
int x, y, ret;
uint8_t *y1 = f->data[0], *y2 = f->data[0] + 8 * f->linesize[0];
uint8_t *u = f->data[1], *v = f->data[2];
if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
if ((ret = bitstream_init8(&bc, buf, buf_size)) < 0)
return ret;
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); \
int res = get_block(&bc, block, c->scan, quant); \
if (res < 0) \
return res; \
if (res > 0) \
@ -142,7 +146,7 @@ int ff_rtjpeg_decode_frame_yuv420(RTJpegContext *c, AVFrame *f,
u += 8 * (f->linesize[1] - w);
v += 8 * (f->linesize[2] - w);
}
return get_bits_count(&gb) / 8;
return bitstream_tell(&bc) / 8;
}
/**

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