mjpegdec.c File Reference

MJPEG decoder. More...

#include "libavutil/imgutils.h"
#include "libavutil/avassert.h"
#include "libavutil/opt.h"
#include "avcodec.h"
#include "blockdsp.h"
#include "copy_block.h"
#include "hwaccel.h"
#include "idctdsp.h"
#include "internal.h"
#include "jpegtables.h"
#include "mjpeg.h"
#include "mjpegdec.h"
#include "jpeglsdec.h"
#include "put_bits.h"
#include "tiff.h"
#include "exif.h"
#include "bytestream.h"

Macros
#define	REFINE_BIT(j)
#define	ZERO_RUN
#define	copy_data_segment(skip)

Functions
av_cold int	ff_mjpeg_decode_init (AVCodecContext *avctx)
int	ff_mjpeg_decode_dqt (MJpegDecodeContext *s)
int	ff_mjpeg_decode_dht (MJpegDecodeContext *s)
int	ff_mjpeg_decode_sof (MJpegDecodeContext *s)
int	ff_mjpeg_decode_sos (MJpegDecodeContext *s, const uint8_t *mb_bitmask, int mb_bitmask_size, const AVFrame *reference)
int	ff_mjpeg_find_marker (MJpegDecodeContext *s, const uint8_t **buf_ptr, const uint8_t *buf_end, const uint8_t **unescaped_buf_ptr, int *unescaped_buf_size)
int	ff_mjpeg_decode_frame (AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
av_cold int	ff_mjpeg_decode_end (AVCodecContext *avctx)

Detailed Description

MJPEG decoder.

Macro Definition Documentation

copy_data_segment

#define copy_data_segment

(

skip

)

Value:

do {       \
            ptrdiff_t length = (ptr - src) - (skip);  \
            if (length > 0) {                         \
                memcpy(dst, src, length);             \
                dst += length;                        \
                src = ptr;                            \
            }                                         \
        } while (0)

REFINE_BIT

#define REFINE_BIT

(

j

)

Value:

{                                             \
    UPDATE_CACHE(re, &s->gb);                                       \
    sign = block[j] >> 15;                                          \
    block[j] += SHOW_UBITS(re, &s->gb, 1) *                         \
                ((quant_matrix[i] ^ sign) - sign) << Al;            \
    LAST_SKIP_BITS(re, &s->gb, 1);                                  \
}

ZERO_RUN

#define ZERO_RUN

Value:

for (; ; i++) {                                                     \
    if (i > last) {                                                 \
        i += run;                                                   \
        if (i > se) {                                               \
            av_log(s->avctx, AV_LOG_ERROR, "error count: %d\n", i); \
            return -1;                                              \
        }                                                           \
        break;                                                      \
    }                                                               \
    j = s->scantable.permutated[i];                                 \
    if (block[j])                                                   \
        REFINE_BIT(j)                                               \
    else if (run-- == 0)                                            \
        break;                                                      \
}