PeerStreamer

/*

 * MJPEG decoder

 * Copyright (c) 2000, 2001 Fabrice Bellard

 * Copyright (c) 2003 Alex Beregszaszi

 * Copyright (c) 2003-2004 Michael Niedermayer

 *

 * Support for external huffman table, various fixes (AVID workaround),

 * aspecting, new decode_frame mechanism and apple mjpeg-b support

 *                                  by Alex Beregszaszi

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg 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,

 * 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

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * MJPEG decoder.

 */

//#define DEBUG

#include <assert.h>

#include "libavcore/imgutils.h"

#include "avcodec.h"

#include "dsputil.h"

#include "mjpeg.h"

#include "mjpegdec.h"

#include "jpeglsdec.h"

static int build_vlc(VLC *vlc, const uint8_t *bits_table, const uint8_t *val_table,

                      int nb_codes, int use_static, int is_ac)

{

    uint8_t huff_size[256];

    uint16_t huff_code[256];

    uint16_t huff_sym[256];

    int i;

    assert(nb_codes <= 256);

    memset(huff_size, 0, sizeof(huff_size));

    ff_mjpeg_build_huffman_codes(huff_size, huff_code, bits_table, val_table);

    for(i=0; i<256; i++)

        huff_sym[i]= i + 16*is_ac;

    if(is_ac) huff_sym[0]= 16*256;

    return init_vlc_sparse(vlc, 9, nb_codes, huff_size, 1, 1, huff_code, 2, 2, huff_sym, 2, 2, use_static);

}

static void build_basic_mjpeg_vlc(MJpegDecodeContext * s) {

    build_vlc(&s->vlcs[0][0], ff_mjpeg_bits_dc_luminance,

              ff_mjpeg_val_dc, 12, 0, 0);

    build_vlc(&s->vlcs[0][1], ff_mjpeg_bits_dc_chrominance,

              ff_mjpeg_val_dc, 12, 0, 0);

    build_vlc(&s->vlcs[1][0], ff_mjpeg_bits_ac_luminance,

              ff_mjpeg_val_ac_luminance, 251, 0, 1);

    build_vlc(&s->vlcs[1][1], ff_mjpeg_bits_ac_chrominance,

              ff_mjpeg_val_ac_chrominance, 251, 0, 1);

    build_vlc(&s->vlcs[2][0], ff_mjpeg_bits_ac_luminance,

              ff_mjpeg_val_ac_luminance, 251, 0, 0);

    build_vlc(&s->vlcs[2][1], ff_mjpeg_bits_ac_chrominance,

              ff_mjpeg_val_ac_chrominance, 251, 0, 0);

}

av_cold int ff_mjpeg_decode_init(AVCodecContext *avctx)

{

    MJpegDecodeContext *s = avctx->priv_data;

    s->avctx = avctx;

    dsputil_init(&s->dsp, avctx);

    ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);

    s->buffer_size = 0;

    s->buffer = NULL;

    s->start_code = -1;

    s->first_picture = 1;

    s->org_height = avctx->coded_height;

    avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;

    build_basic_mjpeg_vlc(s);

    if (avctx->flags & CODEC_FLAG_EXTERN_HUFF)

    {

        av_log(avctx, AV_LOG_INFO, "mjpeg: using external huffman table\n");

        init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size*8);

        if (ff_mjpeg_decode_dht(s)) {

            av_log(avctx, AV_LOG_ERROR, "mjpeg: error using external huffman table, switching back to internal\n");

            build_basic_mjpeg_vlc(s);

        }

    }

    if (avctx->extradata_size > 9 &&

        AV_RL32(avctx->extradata + 4) == MKTAG('f','i','e','l')) {

        if (avctx->extradata[9] == 6) { /* quicktime icefloe 019 */

            s->interlace_polarity = 1; /* bottom field first */

            av_log(avctx, AV_LOG_DEBUG, "mjpeg bottom field first\n");

        }

    }

    if (avctx->codec->id == CODEC_ID_AMV)

        s->flipped = 1;

    return 0;

}

/* quantize tables */

int ff_mjpeg_decode_dqt(MJpegDecodeContext *s)

{

    int len, index, i, j;

    len = get_bits(&s->gb, 16) - 2;

    while (len >= 65) {

        /* only 8 bit precision handled */

        if (get_bits(&s->gb, 4) != 0)

        {

            av_log(s->avctx, AV_LOG_ERROR, "dqt: 16bit precision\n");

            return -1;

        }

        index = get_bits(&s->gb, 4);

        if (index >= 4)

            return -1;

        av_log(s->avctx, AV_LOG_DEBUG, "index=%d\n", index);

        /* read quant table */

        for(i=0;i<64;i++) {

            j = s->scantable.permutated[i];

            s->quant_matrixes[index][j] = get_bits(&s->gb, 8);

        }

        //XXX FIXME finetune, and perhaps add dc too

        s->qscale[index]= FFMAX(

            s->quant_matrixes[index][s->scantable.permutated[1]],

            s->quant_matrixes[index][s->scantable.permutated[8]]) >> 1;

        av_log(s->avctx, AV_LOG_DEBUG, "qscale[%d]: %d\n", index, s->qscale[index]);

        len -= 65;

    }

    return 0;

}

/* decode huffman tables and build VLC decoders */

int ff_mjpeg_decode_dht(MJpegDecodeContext *s)

{

    int len, index, i, class, n, v, code_max;

    uint8_t bits_table[17];

    uint8_t val_table[256];

    len = get_bits(&s->gb, 16) - 2;

    while (len > 0) {

        if (len < 17)

            return -1;

        class = get_bits(&s->gb, 4);

        if (class >= 2)

            return -1;

        index = get_bits(&s->gb, 4);

        if (index >= 4)

            return -1;

        n = 0;

        for(i=1;i<=16;i++) {

            bits_table[i] = get_bits(&s->gb, 8);

            n += bits_table[i];

        }

        len -= 17;

        if (len < n || n > 256)

            return -1;

        code_max = 0;

        for(i=0;i<n;i++) {

            v = get_bits(&s->gb, 8);

            if (v > code_max)

                code_max = v;

            val_table[i] = v;

        }

        len -= n;

        /* build VLC and flush previous vlc if present */

        free_vlc(&s->vlcs[class][index]);

        av_log(s->avctx, AV_LOG_DEBUG, "class=%d index=%d nb_codes=%d\n",

               class, index, code_max + 1);

        if(build_vlc(&s->vlcs[class][index], bits_table, val_table, code_max + 1, 0, class > 0) < 0){

            return -1;

        }

        if(class>0){

            free_vlc(&s->vlcs[2][index]);

            if(build_vlc(&s->vlcs[2][index], bits_table, val_table, code_max + 1, 0, 0) < 0){

            return -1;

            }

        }

    }

    return 0;

}

int ff_mjpeg_decode_sof(MJpegDecodeContext *s)

{

    int len, nb_components, i, width, height, pix_fmt_id;

    /* XXX: verify len field validity */

    len = get_bits(&s->gb, 16);

    s->bits= get_bits(&s->gb, 8);

    if(s->pegasus_rct) s->bits=9;

    if(s->bits==9 && !s->pegasus_rct) s->rct=1;    //FIXME ugly

    if (s->bits != 8 && !s->lossless){

        av_log(s->avctx, AV_LOG_ERROR, "only 8 bits/component accepted\n");

        return -1;

    }

    height = get_bits(&s->gb, 16);

    width = get_bits(&s->gb, 16);

    //HACK for odd_height.mov

    if(s->interlaced && s->width == width && s->height == height + 1)

        height= s->height;

    av_log(s->avctx, AV_LOG_DEBUG, "sof0: picture: %dx%d\n", width, height);

    if(av_image_check_size(width, height, 0, s->avctx))

        return -1;

    nb_components = get_bits(&s->gb, 8);

    if (nb_components <= 0 ||

        nb_components > MAX_COMPONENTS)

        return -1;

    if (s->ls && !(s->bits <= 8 || nb_components == 1)){

        av_log(s->avctx, AV_LOG_ERROR, "only <= 8 bits/component or 16-bit gray accepted for JPEG-LS\n");

        return -1;

    }

    s->nb_components = nb_components;

    s->h_max = 1;

    s->v_max = 1;

    for(i=0;i<nb_components;i++) {

        /* component id */

        s->component_id[i] = get_bits(&s->gb, 8) - 1;

        s->h_count[i] = get_bits(&s->gb, 4);

        s->v_count[i] = get_bits(&s->gb, 4);

        /* compute hmax and vmax (only used in interleaved case) */

        if (s->h_count[i] > s->h_max)

            s->h_max = s->h_count[i];

        if (s->v_count[i] > s->v_max)

            s->v_max = s->v_count[i];

        s->quant_index[i] = get_bits(&s->gb, 8);

        if (s->quant_index[i] >= 4)

            return -1;

        av_log(s->avctx, AV_LOG_DEBUG, "component %d %d:%d id: %d quant:%d\n", i, s->h_count[i],

               s->v_count[i], s->component_id[i], s->quant_index[i]);

    }

    if(s->ls && (s->h_max > 1 || s->v_max > 1)) {

        av_log(s->avctx, AV_LOG_ERROR, "Subsampling in JPEG-LS is not supported.\n");

        return -1;

    }

    if(s->v_max==1 && s->h_max==1 && s->lossless==1) s->rgb=1;

    /* if different size, realloc/alloc picture */

    /* XXX: also check h_count and v_count */

    if (width != s->width || height != s->height) {

        av_freep(&s->qscale_table);

        s->width = width;

        s->height = height;

        s->interlaced = 0;

        /* test interlaced mode */

        if (s->first_picture &&

            s->org_height != 0 &&

            s->height < ((s->org_height * 3) / 4)) {

            s->interlaced = 1;

            s->bottom_field = s->interlace_polarity;

            s->picture.interlaced_frame = 1;

            s->picture.top_field_first = !s->interlace_polarity;

            height *= 2;

        }

        avcodec_set_dimensions(s->avctx, width, height);

        s->qscale_table= av_mallocz((s->width+15)/16);

        s->first_picture = 0;

    }

    if(s->interlaced && (s->bottom_field == !s->interlace_polarity))

        return 0;

    /* XXX: not complete test ! */

    pix_fmt_id = (s->h_count[0] << 28) | (s->v_count[0] << 24) |

                 (s->h_count[1] << 20) | (s->v_count[1] << 16) |

                 (s->h_count[2] << 12) | (s->v_count[2] <<  8) |

                 (s->h_count[3] <<  4) |  s->v_count[3];

    av_log(s->avctx, AV_LOG_DEBUG, "pix fmt id %x\n", pix_fmt_id);

    //NOTE we do not allocate pictures large enough for the possible padding of h/v_count being 4

    if(!(pix_fmt_id & 0xD0D0D0D0))

        pix_fmt_id-= (pix_fmt_id & 0xF0F0F0F0)>>1;

    if(!(pix_fmt_id & 0x0D0D0D0D))

        pix_fmt_id-= (pix_fmt_id & 0x0F0F0F0F)>>1;

    switch(pix_fmt_id){

    case 0x11111100:

        if(s->rgb){

            s->avctx->pix_fmt = PIX_FMT_BGRA;

        }else

            s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV444P : PIX_FMT_YUVJ444P;

        assert(s->nb_components==3);

        break;

    case 0x11000000:

        s->avctx->pix_fmt = PIX_FMT_GRAY8;

        break;

    case 0x12111100:

        s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV440P : PIX_FMT_YUVJ440P;

        break;

    case 0x21111100:

        s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV422P : PIX_FMT_YUVJ422P;

        break;

    case 0x22111100:

        s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV420P : PIX_FMT_YUVJ420P;

        break;

    default:

        av_log(s->avctx, AV_LOG_ERROR, "Unhandled pixel format 0x%x\n", pix_fmt_id);

        return -1;

    }

    if(s->ls){

        if(s->nb_components > 1)

            s->avctx->pix_fmt = PIX_FMT_RGB24;

        else if(s->bits <= 8)

            s->avctx->pix_fmt = PIX_FMT_GRAY8;

        else

            s->avctx->pix_fmt = PIX_FMT_GRAY16;

    }

    if(s->picture.data[0])

        s->avctx->release_buffer(s->avctx, &s->picture);

    s->picture.reference= 0;

    if(s->avctx->get_buffer(s->avctx, &s->picture) < 0){

        av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");

        return -1;

    }

    s->picture.pict_type= FF_I_TYPE;

    s->picture.key_frame= 1;

    s->got_picture = 1;

    for(i=0; i<3; i++){

        s->linesize[i]= s->picture.linesize[i] << s->interlaced;

    }

//    printf("%d %d %d %d %d %d\n", s->width, s->height, s->linesize[0], s->linesize[1], s->interlaced, s->avctx->height);

    if (len != (8+(3*nb_components)))

    {

        av_log(s->avctx, AV_LOG_DEBUG, "decode_sof0: error, len(%d) mismatch\n", len);

    }

    /* totally blank picture as progressive JPEG will only add details to it */

    if(s->progressive){

        int bw = (width  + s->h_max*8-1) / (s->h_max*8);

        int bh = (height + s->v_max*8-1) / (s->v_max*8);

        for(i=0; i<s->nb_components; i++) {

            int size = bw * bh * s->h_count[i] * s->v_count[i];

            av_freep(&s->blocks[i]);

            av_freep(&s->last_nnz[i]);

            s->blocks[i] = av_malloc(size * sizeof(**s->blocks));

            s->last_nnz[i] = av_mallocz(size * sizeof(**s->last_nnz));

            s->block_stride[i] = bw * s->h_count[i];

        }

        memset(s->coefs_finished, 0, sizeof(s->coefs_finished));

    }

    return 0;

}

static inline int mjpeg_decode_dc(MJpegDecodeContext *s, int dc_index)

{

    int code;

    code = get_vlc2(&s->gb, s->vlcs[0][dc_index].table, 9, 2);

    if (code < 0)

    {

        av_log(s->avctx, AV_LOG_WARNING, "mjpeg_decode_dc: bad vlc: %d:%d (%p)\n", 0, dc_index,

               &s->vlcs[0][dc_index]);

        return 0xffff;

    }

    if(code)

        return get_xbits(&s->gb, code);

    else

        return 0;

}

/* decode block and dequantize */

static int decode_block(MJpegDecodeContext *s, DCTELEM *block,

                        int component, int dc_index, int ac_index, int16_t *quant_matrix)

{

    int code, i, j, level, val;

    /* DC coef */

    val = mjpeg_decode_dc(s, dc_index);

    if (val == 0xffff) {

        av_log(s->avctx, AV_LOG_ERROR, "error dc\n");

        return -1;

    }

    val = val * quant_matrix[0] + s->last_dc[component];

    s->last_dc[component] = val;

    block[0] = val;

    /* AC coefs */

    i = 0;

    {OPEN_READER(re, &s->gb);

    do {

        UPDATE_CACHE(re, &s->gb);

        GET_VLC(code, re, &s->gb, s->vlcs[1][ac_index].table, 9, 2);

        i += ((unsigned)code) >> 4;

            code &= 0xf;

        if(code){

            if(code > MIN_CACHE_BITS - 16){

                UPDATE_CACHE(re, &s->gb);

            }

            {

                int cache=GET_CACHE(re,&s->gb);

                int sign=(~cache)>>31;

                level = (NEG_USR32(sign ^ cache,code) ^ sign) - sign;

            }

            LAST_SKIP_BITS(re, &s->gb, code);

            if (i > 63) {

                av_log(s->avctx, AV_LOG_ERROR, "error count: %d\n", i);

                return -1;

            }

            j = s->scantable.permutated[i];

            block[j] = level * quant_matrix[j];

        }

    }while(i<63);

    CLOSE_READER(re, &s->gb);}

    return 0;

}

static int decode_dc_progressive(MJpegDecodeContext *s, DCTELEM *block, int component,

                                 int dc_index, int16_t *quant_matrix, int Al)

{

    int val;

    s->dsp.clear_block(block);

    val = mjpeg_decode_dc(s, dc_index);

    if (val == 0xffff) {

        av_log(s->avctx, AV_LOG_ERROR, "error dc\n");

        return -1;

    }

    val = (val * quant_matrix[0] << Al) + s->last_dc[component];

    s->last_dc[component] = val;

    block[0] = val;

    return 0;

}

/* decode block and dequantize - progressive JPEG version */

static int decode_block_progressive(MJpegDecodeContext *s, DCTELEM *block, uint8_t *last_nnz,

                                    int ac_index, int16_t *quant_matrix,

                                    int ss, int se, int Al, int *EOBRUN)

{

    int code, i, j, level, val, run;

    if(*EOBRUN){

        (*EOBRUN)--;

        return 0;

    }

    {OPEN_READER(re, &s->gb);

    for(i=ss;;i++) {

        UPDATE_CACHE(re, &s->gb);

        GET_VLC(code, re, &s->gb, s->vlcs[2][ac_index].table, 9, 2);

        run = ((unsigned) code) >> 4;

        code &= 0xF;

        if(code) {

            i += run;

            if(code > MIN_CACHE_BITS - 16){

                UPDATE_CACHE(re, &s->gb);

            }

            {

                int cache=GET_CACHE(re,&s->gb);

                int sign=(~cache)>>31;

                level = (NEG_USR32(sign ^ cache,code) ^ sign) - sign;

            }

            LAST_SKIP_BITS(re, &s->gb, code);

            if (i >= se) {

                if(i == se){

                    j = s->scantable.permutated[se];

                    block[j] = level * quant_matrix[j] << Al;

                    break;

                }

                av_log(s->avctx, AV_LOG_ERROR, "error count: %d\n", i);

                return -1;

            }

            j = s->scantable.permutated[i];

            block[j] = level * quant_matrix[j] << Al;

        }else{

            if(run == 0xF){// ZRL - skip 15 coefficients

                i += 15;

                if (i >= se) {

                    av_log(s->avctx, AV_LOG_ERROR, "ZRL overflow: %d\n", i);

                    return -1;

                }

            }else{

                val = (1 << run);

                if(run){

                    UPDATE_CACHE(re, &s->gb);

                    val += NEG_USR32(GET_CACHE(re, &s->gb), run);

                    LAST_SKIP_BITS(re, &s->gb, run);

                }

                *EOBRUN = val - 1;

                break;

            }

        }

    }

    CLOSE_READER(re, &s->gb);}

    if(i > *last_nnz)

        *last_nnz = i;

    return 0;

}

#define REFINE_BIT(j) {\

    UPDATE_CACHE(re, &s->gb);\

    sign = block[j]>>15;\

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

    LAST_SKIP_BITS(re, &s->gb, 1);\

}

#define ZERO_RUN \

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;\

}

/* decode block and dequantize - progressive JPEG refinement pass */

static int decode_block_refinement(MJpegDecodeContext *s, DCTELEM *block, uint8_t *last_nnz,

                        int ac_index, int16_t *quant_matrix,

                        int ss, int se, int Al, int *EOBRUN)

{

    int code, i=ss, j, sign, val, run;

    int last = FFMIN(se, *last_nnz);

    OPEN_READER(re, &s->gb);

    if(*EOBRUN)

        (*EOBRUN)--;

    else {

        for(;;i++) {

            UPDATE_CACHE(re, &s->gb);

            GET_VLC(code, re, &s->gb, s->vlcs[2][ac_index].table, 9, 2);

            if(code & 0xF) {

                run = ((unsigned) code) >> 4;

                UPDATE_CACHE(re, &s->gb);

                val = SHOW_UBITS(re, &s->gb, 1);

                LAST_SKIP_BITS(re, &s->gb, 1);

                ZERO_RUN;

                j = s->scantable.permutated[i];

                val--;

                block[j] = ((quant_matrix[j]^val)-val) << Al;

                if(i == se) {

                    if(i > *last_nnz)

                        *last_nnz = i;

                    CLOSE_READER(re, &s->gb);

                    return 0;

                }

            }else{

                run = ((unsigned) code) >> 4;

                if(run == 0xF){

                    ZERO_RUN;

                }else{

                    val = run;

                    run = (1 << run);

                    if(val) {

                        UPDATE_CACHE(re, &s->gb);

                        run += SHOW_UBITS(re, &s->gb, val);

                        LAST_SKIP_BITS(re, &s->gb, val);

                    }

                    *EOBRUN = run - 1;

                    break;

                }

            }

        }

        if(i > *last_nnz)

            *last_nnz = i;

    }

    for(;i<=last;i++) {

        j = s->scantable.permutated[i];

        if(block[j])

            REFINE_BIT(j)

    }

    CLOSE_READER(re, &s->gb);

    return 0;

}

#undef REFINE_BIT

#undef ZERO_RUN

static int ljpeg_decode_rgb_scan(MJpegDecodeContext *s, int predictor, int point_transform){

    int i, mb_x, mb_y;

    uint16_t (*buffer)[4];

    int left[3], top[3], topleft[3];

    const int linesize= s->linesize[0];

    const int mask= (1<<s->bits)-1;

    av_fast_malloc(&s->ljpeg_buffer, &s->ljpeg_buffer_size, (unsigned)s->mb_width * 4 * sizeof(s->ljpeg_buffer[0][0]));

    buffer= s->ljpeg_buffer;

    for(i=0; i<3; i++){

        buffer[0][i]= 1 << (s->bits + point_transform - 1);

    }

    for(mb_y = 0; mb_y < s->mb_height; mb_y++) {

        const int modified_predictor= mb_y ? predictor : 1;

        uint8_t *ptr = s->picture.data[0] + (linesize * mb_y);

        if (s->interlaced && s->bottom_field)

            ptr += linesize >> 1;

        for(i=0; i<3; i++){

            top[i]= left[i]= topleft[i]= buffer[0][i];

        }

        for(mb_x = 0; mb_x < s->mb_width; mb_x++) {

            if (s->restart_interval && !s->restart_count)

                s->restart_count = s->restart_interval;

            for(i=0;i<3;i++) {

                int pred;

                topleft[i]= top[i];

                top[i]= buffer[mb_x][i];

                PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);

                left[i]=

                buffer[mb_x][i]= mask & (pred + (mjpeg_decode_dc(s, s->dc_index[i]) << point_transform));

            }

            if (s->restart_interval && !--s->restart_count) {

                align_get_bits(&s->gb);

                skip_bits(&s->gb, 16); /* skip RSTn */

            }

        }

        if(s->rct){

            for(mb_x = 0; mb_x < s->mb_width; mb_x++) {

                ptr[4*mb_x+1] = buffer[mb_x][0] - ((buffer[mb_x][1] + buffer[mb_x][2] - 0x200)>>2);

                ptr[4*mb_x+0] = buffer[mb_x][1] + ptr[4*mb_x+1];

                ptr[4*mb_x+2] = buffer[mb_x][2] + ptr[4*mb_x+1];

            }

        }else if(s->pegasus_rct){

            for(mb_x = 0; mb_x < s->mb_width; mb_x++) {

                ptr[4*mb_x+1] = buffer[mb_x][0] - ((buffer[mb_x][1] + buffer[mb_x][2])>>2);

                ptr[4*mb_x+0] = buffer[mb_x][1] + ptr[4*mb_x+1];

                ptr[4*mb_x+2] = buffer[mb_x][2] + ptr[4*mb_x+1];

            }

        }else{

            for(mb_x = 0; mb_x < s->mb_width; mb_x++) {

                ptr[4*mb_x+0] = buffer[mb_x][2];

                ptr[4*mb_x+1] = buffer[mb_x][1];

                ptr[4*mb_x+2] = buffer[mb_x][0];

            }

        }

    }

    return 0;

}

static int ljpeg_decode_yuv_scan(MJpegDecodeContext *s, int predictor, int point_transform){

    int i, mb_x, mb_y;

    const int nb_components=3;

    for(mb_y = 0; mb_y < s->mb_height; mb_y++) {

        for(mb_x = 0; mb_x < s->mb_width; mb_x++) {

            if (s->restart_interval && !s->restart_count)

                s->restart_count = s->restart_interval;

            if(mb_x==0 || mb_y==0 || s->interlaced){

                for(i=0;i<nb_components;i++) {

                    uint8_t *ptr;

                    int n, h, v, x, y, c, j, linesize;

                    n = s->nb_blocks[i];

                    c = s->comp_index[i];

                    h = s->h_scount[i];

                    v = s->v_scount[i];

                    x = 0;

                    y = 0;

                    linesize= s->linesize[c];

                    for(j=0; j<n; j++) {

                        int pred;

                        ptr = s->picture.data[c] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap

                        if(y==0 && mb_y==0){

                            if(x==0 && mb_x==0){

                                pred= 128 << point_transform;

                            }else{

                                pred= ptr[-1];

                            }

                        }else{

                            if(x==0 && mb_x==0){

                                pred= ptr[-linesize];

                            }else{

                                PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);

                            }

                        }

                        if (s->interlaced && s->bottom_field)

                            ptr += linesize >> 1;

                        *ptr= pred + (mjpeg_decode_dc(s, s->dc_index[i]) << point_transform);

                        if (++x == h) {

                            x = 0;

                            y++;

                        }

                    }

                }

            }else{

                for(i=0;i<nb_components;i++) {

                    uint8_t *ptr;

                    int n, h, v, x, y, c, j, linesize;

                    n = s->nb_blocks[i];

                    c = s->comp_index[i];

                    h = s->h_scount[i];

                    v = s->v_scount[i];

                    x = 0;

                    y = 0;

                    linesize= s->linesize[c];

                    for(j=0; j<n; j++) {

                        int pred;

                        ptr = s->picture.data[c] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap

                        PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);

                        *ptr= pred + (mjpeg_decode_dc(s, s->dc_index[i]) << point_transform);

                        if (++x == h) {

                            x = 0;

                            y++;

                        }

                    }

                }

            }

            if (s->restart_interval && !--s->restart_count) {

                align_get_bits(&s->gb);

                skip_bits(&s->gb, 16); /* skip RSTn */

            }

        }

    }

    return 0;

}

static int mjpeg_decode_scan(MJpegDecodeContext *s, int nb_components, int Ah, int Al){

    int i, mb_x, mb_y;

    uint8_t* data[MAX_COMPONENTS];

    int linesize[MAX_COMPONENTS];

    if(s->flipped && s->avctx->flags & CODEC_FLAG_EMU_EDGE) {

        av_log(s->avctx, AV_LOG_ERROR, "Can not flip image with CODEC_FLAG_EMU_EDGE set!\n");

        s->flipped = 0;

    }

    for(i=0; i < nb_components; i++) {

        int c = s->comp_index[i];

        data[c] = s->picture.data[c];

        linesize[c]=s->linesize[c];

        s->coefs_finished[c] |= 1;

        if(s->flipped) {

            //picture should be flipped upside-down for this codec

            data[c] += (linesize[c] * (s->v_scount[i] * (8 * s->mb_height -((s->height/s->v_max)&7)) - 1 ));

            linesize[c] *= -1;

        }

    }

    for(mb_y = 0; mb_y < s->mb_height; mb_y++) {

        for(mb_x = 0; mb_x < s->mb_width; mb_x++) {

            if (s->restart_interval && !s->restart_count)

                s->restart_count = s->restart_interval;

            for(i=0;i<nb_components;i++) {

                uint8_t *ptr;

                int n, h, v, x, y, c, j;

                n = s->nb_blocks[i];

                c = s->comp_index[i];

                h = s->h_scount[i];

                v = s->v_scount[i];

                x = 0;

                y = 0;

                for(j=0;j<n;j++) {

                    ptr = data[c] +

                        (((linesize[c] * (v * mb_y + y) * 8) +

                        (h * mb_x + x) * 8) >> s->avctx->lowres);

                    if(s->interlaced && s->bottom_field)

                        ptr += linesize[c] >> 1;

                    if(!s->progressive) {

                        s->dsp.clear_block(s->block);

                        if(decode_block(s, s->block, i,

                                     s->dc_index[i], s->ac_index[i],

                                     s->quant_matrixes[ s->quant_index[c] ]) < 0) {

                            av_log(s->avctx, AV_LOG_ERROR, "error y=%d x=%d\n", mb_y, mb_x);

                            return -1;

                        }

                        s->dsp.idct_put(ptr, linesize[c], s->block);

                    } else {

                        int block_idx = s->block_stride[c] * (v * mb_y + y) + (h * mb_x + x);

                        DCTELEM *block = s->blocks[c][block_idx];

                        if(Ah)

                            block[0] += get_bits1(&s->gb) * s->quant_matrixes[ s->quant_index[c] ][0] << Al;

                        else if(decode_dc_progressive(s, block, i, s->dc_index[i], s->quant_matrixes[ s->quant_index[c] ], Al) < 0) {

                            av_log(s->avctx, AV_LOG_ERROR, "error y=%d x=%d\n", mb_y, mb_x);

                            return -1;

                        }

                    }

//                    av_log(s->avctx, AV_LOG_DEBUG, "mb: %d %d processed\n", mb_y, mb_x);

//av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d %d %d %d %d \n", mb_x, mb_y, x, y, c, s->bottom_field, (v * mb_y + y) * 8, (h * mb_x + x) * 8);

                    if (++x == h) {

                        x = 0;

                        y++;

                    }

                }

            }

            if (s->restart_interval && !--s->restart_count) {

                align_get_bits(&s->gb);

                skip_bits(&s->gb, 16); /* skip RSTn */

                for (i=0; i<nb_components; i++) /* reset dc */

                    s->last_dc[i] = 1024;

            }

        }

    }

    return 0;

}

static int mjpeg_decode_scan_progressive_ac(MJpegDecodeContext *s, int ss, int se, int Ah, int Al){

    int mb_x, mb_y;

    int EOBRUN = 0;

    int c = s->comp_index[0];

    uint8_t* data = s->picture.data[c];

    int linesize = s->linesize[c];

    int last_scan = 0;

    int16_t *quant_matrix = s->quant_matrixes[ s->quant_index[c] ];

    if(!Al) {

        s->coefs_finished[c] |= (1LL<<(se+1))-(1LL<<ss);

        last_scan = !~s->coefs_finished[c];

    }

    if(s->interlaced && s->bottom_field)

        data += linesize >> 1;

    for(mb_y = 0; mb_y < s->mb_height; mb_y++) {

        uint8_t *ptr = data + (mb_y*linesize*8 >> s->avctx->lowres);

        int block_idx = mb_y * s->block_stride[c];

        DCTELEM (*block)[64] = &s->blocks[c][block_idx];

        uint8_t *last_nnz = &s->last_nnz[c][block_idx];

        for(mb_x = 0; mb_x < s->mb_width; mb_x++, block++, last_nnz++) {

            int ret;

            if(Ah)

                ret = decode_block_refinement(s, *block, last_nnz, s->ac_index[0],

                                              quant_matrix, ss, se, Al, &EOBRUN);

            else

                ret = decode_block_progressive(s, *block, last_nnz, s->ac_index[0],

                                               quant_matrix, ss, se, Al, &EOBRUN);

            if(ret < 0) {

                av_log(s->avctx, AV_LOG_ERROR, "error y=%d x=%d\n", mb_y, mb_x);

                return -1;

            }

            if(last_scan) {

                s->dsp.idct_put(ptr, linesize, *block);

                ptr += 8 >> s->avctx->lowres;

            }

        }

    }

    return 0;

}

int ff_mjpeg_decode_sos(MJpegDecodeContext *s)

{

    int len, nb_components, i, h, v, predictor, point_transform;

    int index, id;

    const int block_size= s->lossless ? 1 : 8;

    int ilv, prev_shift;

    /* XXX: verify len field validity */

    len = get_bits(&s->gb, 16);

    nb_components = get_bits(&s->gb, 8);

    if (nb_components == 0 || nb_components > MAX_COMPONENTS){

        av_log(s->avctx, AV_LOG_ERROR, "decode_sos: nb_components (%d) unsupported\n", nb_components);

        return -1;

    }

    if (len != 6+2*nb_components)

    {

        av_log(s->avctx, AV_LOG_ERROR, "decode_sos: invalid len (%d)\n", len);

        return -1;

    }

    for(i=0;i<nb_components;i++) {

        id = get_bits(&s->gb, 8) - 1;

        av_log(s->avctx, AV_LOG_DEBUG, "component: %d\n", id);

        /* find component index */

        for(index=0;index<s->nb_components;index++)

            if (id == s->component_id[index])

                break;

        if (index == s->nb_components)

        {

            av_log(s->avctx, AV_LOG_ERROR, "decode_sos: index(%d) out of components\n", index);

            return -1;

        }

        /* Metasoft MJPEG codec has Cb and Cr swapped */

        if (s->avctx->codec_tag == MKTAG('M', 'T', 'S', 'J')

            && nb_components == 3 && s->nb_components == 3 && i)

            index = 3 - i;

        s->comp_index[i] = index;

        s->nb_blocks[i] = s->h_count[index] * s->v_count[index];

        s->h_scount[i] = s->h_count[index];

        s->v_scount[i] = s->v_count[index];

        s->dc_index[i] = get_bits(&s->gb, 4);

        s->ac_index[i] = get_bits(&s->gb, 4);

        if (s->dc_index[i] <  0 || s->ac_index[i] < 0 ||

            s->dc_index[i] >= 4 || s->ac_index[i] >= 4)

            goto out_of_range;

        if (!s->vlcs[0][s->dc_index[i]].table || !s->vlcs[1][s->ac_index[i]].table)

            goto out_of_range;

    }

    predictor= get_bits(&s->gb, 8); /* JPEG Ss / lossless JPEG predictor /JPEG-LS NEAR */

    ilv= get_bits(&s->gb, 8);    /* JPEG Se / JPEG-LS ILV */

    prev_shift = get_bits(&s->gb, 4); /* Ah */

    point_transform= get_bits(&s->gb, 4); /* Al */

    for(i=0;i<nb_components;i++)

        s->last_dc[i] = 1024;

    if (nb_components > 1) {

        /* interleaved stream */

        s->mb_width  = (s->width  + s->h_max * block_size - 1) / (s->h_max * block_size);

        s->mb_height = (s->height + s->v_max * block_size - 1) / (s->v_max * block_size);

    } else if(!s->ls) { /* skip this for JPEG-LS */

        h = s->h_max / s->h_scount[0];

        v = s->v_max / s->v_scount[0];

        s->mb_width  = (s->width  + h * block_size - 1) / (h * block_size);

        s->mb_height = (s->height + v * block_size - 1) / (v * block_size);

        s->nb_blocks[0] = 1;

        s->h_scount[0] = 1;

        s->v_scount[0] = 1;

    }

    if(s->avctx->debug & FF_DEBUG_PICT_INFO)

        av_log(s->avctx, AV_LOG_DEBUG, "%s %s p:%d >>:%d ilv:%d bits:%d %s\n", s->lossless ? "lossless" : "sequential DCT", s->rgb ? "RGB" : "",

               predictor, point_transform, ilv, s->bits,

               s->pegasus_rct ? "PRCT" : (s->rct ? "RCT" : ""));

    /* mjpeg-b can have padding bytes between sos and image data, skip them */

    for (i = s->mjpb_skiptosod; i > 0; i--)

        skip_bits(&s->gb, 8);

    if(s->lossless){

        if(CONFIG_JPEGLS_DECODER && s->ls){

//            for(){

//            reset_ls_coding_parameters(s, 0);

            if(ff_jpegls_decode_picture(s, predictor, point_transform, ilv) < 0)

                return -1;

        }else{

            if(s->rgb){

                if(ljpeg_decode_rgb_scan(s, predictor, point_transform) < 0)

                    return -1;

            }else{

                if(ljpeg_decode_yuv_scan(s, predictor, point_transform) < 0)

                    return -1;

            }

        }

    }else{

        if(s->progressive && predictor) {

            if(mjpeg_decode_scan_progressive_ac(s, predictor, ilv, prev_shift, point_transform) < 0)

                return -1;

        } else {

            if(mjpeg_decode_scan(s, nb_components, prev_shift, point_transform) < 0)

                return -1;

        }

    }

    emms_c();

    return 0;

 out_of_range:

    av_log(s->avctx, AV_LOG_ERROR, "decode_sos: ac/dc index out of range\n");

    return -1;

}

static int mjpeg_decode_dri(MJpegDecodeContext *s)

{

    if (get_bits(&s->gb, 16) != 4)

        return -1;

    s->restart_interval = get_bits(&s->gb, 16);

    s->restart_count = 0;

    av_log(s->avctx, AV_LOG_DEBUG, "restart interval: %d\n", s->restart_interval);

    return 0;

}

static int mjpeg_decode_app(MJpegDecodeContext *s)

{

    int len, id, i;

    len = get_bits(&s->gb, 16);

    if (len < 5)

        return -1;

    if(8*len + get_bits_count(&s->gb) > s->gb.size_in_bits)

        return -1;

    id = get_bits_long(&s->gb, 32);

    id = av_be2ne32(id);

    len -= 6;

    if(s->avctx->debug & FF_DEBUG_STARTCODE){

        av_log(s->avctx, AV_LOG_DEBUG, "APPx %8X\n", id);

    }

    /* buggy AVID, it puts EOI only at every 10th frame */

    /* also this fourcc is used by non-avid files too, it holds some

       informations, but it's always present in AVID creates files */

    if (id == AV_RL32("AVI1"))

    {

        /* structure:

            4bytes      AVI1

            1bytes      polarity

            1bytes      always zero

            4bytes      field_size

            4bytes      field_size_less_padding

        */

            s->buggy_avid = 1;

//        if (s->first_picture)

//            printf("mjpeg: workarounding buggy AVID\n");

        i = get_bits(&s->gb, 8);

        if     (i==2) s->bottom_field= 1;

        else if(i==1) s->bottom_field= 0;

#if 0

        skip_bits(&s->gb, 8);

        skip_bits(&s->gb, 32);

        skip_bits(&s->gb, 32);

        len -= 10;

#endif

//        if (s->interlace_polarity)

//            printf("mjpeg: interlace polarity: %d\n", s->interlace_polarity);

        goto out;

    }

//    len -= 2;

    if (id == AV_RL32("JFIF"))

    {

        int t_w, t_h, v1, v2;

        skip_bits(&s->gb, 8); /* the trailing zero-byte */

        v1= get_bits(&s->gb, 8);

        v2= get_bits(&s->gb, 8);

        skip_bits(&s->gb, 8);

        s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 16);

        s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 16);

        if (s->avctx->debug & FF_DEBUG_PICT_INFO)

            av_log(s->avctx, AV_LOG_INFO, "mjpeg: JFIF header found (version: %x.%x) SAR=%d/%d\n",

                v1, v2,

                s->avctx->sample_aspect_ratio.num,

                s->avctx->sample_aspect_ratio.den

            );

        t_w = get_bits(&s->gb, 8);

        t_h = get_bits(&s->gb, 8);

        if (t_w && t_h)

        {

            /* skip thumbnail */

            if (len-10-(t_w*t_h*3) > 0)

                len -= t_w*t_h*3;

        }

        len -= 10;

        goto out;

    }

    if (id == AV_RL32("Adob") && (get_bits(&s->gb, 8) == 'e'))

    {

        if (s->avctx->debug & FF_DEBUG_PICT_INFO)

            av_log(s->avctx, AV_LOG_INFO, "mjpeg: Adobe header found\n");

        skip_bits(&s->gb, 16); /* version */

        skip_bits(&s->gb, 16); /* flags0 */

        skip_bits(&s->gb, 16); /* flags1 */

        skip_bits(&s->gb, 8);  /* transform */

        len -= 7;

        goto out;

    }

    if (id == AV_RL32("LJIF")){

        if (s->avctx->debug & FF_DEBUG_PICT_INFO)

            av_log(s->avctx, AV_LOG_INFO, "Pegasus lossless jpeg header found\n");

        skip_bits(&s->gb, 16); /* version ? */

        skip_bits(&s->gb, 16); /* unknwon always 0? */

        skip_bits(&s->gb, 16); /* unknwon always 0? */

        skip_bits(&s->gb, 16); /* unknwon always 0? */

        switch( get_bits(&s->gb, 8)){

        case 1:

            s->rgb= 1;

            s->pegasus_rct=0;

            break;

        case 2:

            s->rgb= 1;

            s->pegasus_rct=1;

            break;

        default:

            av_log(s->avctx, AV_LOG_ERROR, "unknown colorspace\n");

        }

        len -= 9;

        goto out;

    }

    /* Apple MJPEG-A */

    if ((s->start_code == APP1) && (len > (0x28 - 8)))

    {

        id = get_bits_long(&s->gb, 32);

        id = av_be2ne32(id);

        len -= 4;

        if (id == AV_RL32("mjpg")) /* Apple MJPEG-A */

        {

#if 0

            skip_bits(&s->gb, 32); /* field size */

            skip_bits(&s->gb, 32); /* pad field size */

            skip_bits(&s->gb, 32); /* next off */

            skip_bits(&s->gb, 32); /* quant off */

            skip_bits(&s->gb, 32); /* huff off */

            skip_bits(&s->gb, 32); /* image off */

            skip_bits(&s->gb, 32); /* scan off */

            skip_bits(&s->gb, 32); /* data off */

#endif

            if (s->avctx->debug & FF_DEBUG_PICT_INFO)

                av_log(s->avctx, AV_LOG_INFO, "mjpeg: Apple MJPEG-A header found\n");

        }

    }

out:

    /* slow but needed for extreme adobe jpegs */

    if (len < 0)

        av_log(s->avctx, AV_LOG_ERROR, "mjpeg: error, decode_app parser read over the end\n");

    while(--len > 0)

        skip_bits(&s->gb, 8);

    return 0;

}

static int mjpeg_decode_com(MJpegDecodeContext *s)

{

    int len = get_bits(&s->gb, 16);

    if (len >= 2 && 8*len - 16 + get_bits_count(&s->gb) <= s->gb.size_in_bits) {

        char *cbuf = av_malloc(len - 1);

        if (cbuf) {

            int i;

            for (i = 0; i < len - 2; i++)

                cbuf[i] = get_bits(&s->gb, 8);

            if (i > 0 && cbuf[i-1] == '\n')

                cbuf[i-1] = 0;

            else

                cbuf[i] = 0;

            if(s->avctx->debug & FF_DEBUG_PICT_INFO)

                av_log(s->avctx, AV_LOG_INFO, "mjpeg comment: '%s'\n", cbuf);

            /* buggy avid, it puts EOI only at every 10th frame */

            if (!strcmp(cbuf, "AVID"))

            {

                s->buggy_avid = 1;

                //        if (s->first_picture)

                //            printf("mjpeg: workarounding buggy AVID\n");

            }

            else if(!strcmp(cbuf, "CS=ITU601")){

                s->cs_itu601= 1;

            }

            else if((len > 20 && !strncmp(cbuf, "Intel(R) JPEG Library", 21)) ||

                    (len > 19 && !strncmp(cbuf, "Metasoft MJPEG Codec", 20))){

                s->flipped = 1;

            }

            av_free(cbuf);

        }

    }

    return 0;

}

#if 0

static int valid_marker_list[] =

{

        /* 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f */

/* 0 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* 1 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* 2 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* 3 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* 4 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* 5 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* 6 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* 7 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* 8 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* 9 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* a */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* b */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

/* c */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

/* d */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

/* e */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

/* f */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,

}

#endif

/* return the 8 bit start code value and update the search

   state. Return -1 if no start code found */

static int find_marker(const uint8_t **pbuf_ptr, const uint8_t *buf_end)

{

    const uint8_t *buf_ptr;

    unsigned int v, v2;

    int val;

#ifdef DEBUG

    int skipped=0;

#endif

    buf_ptr = *pbuf_ptr;

    while (buf_ptr < buf_end) {

        v = *buf_ptr++;

        v2 = *buf_ptr;

        if ((v == 0xff) && (v2 >= 0xc0) && (v2 <= 0xfe) && buf_ptr < buf_end) {

            val = *buf_ptr++;

            goto found;

        }

#ifdef DEBUG

        skipped++;

#endif

    }

    val = -1;

found:

    dprintf(NULL, "find_marker skipped %d bytes\n", skipped);

    *pbuf_ptr = buf_ptr;

    return val;

}

int ff_mjpeg_decode_frame(AVCodecContext *avctx,

                              void *data, int *data_size,

                              AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    MJpegDecodeContext *s = avctx->priv_data;

    const uint8_t *buf_end, *buf_ptr;

    int start_code;

    AVFrame *picture = data;

    s->got_picture = 0; // picture from previous image can not be reused

    buf_ptr = buf;

    buf_end = buf + buf_size;

    while (buf_ptr < buf_end) {

        /* find start next marker */

        start_code = find_marker(&buf_ptr, buf_end);

        {

            /* EOF */

            if (start_code < 0) {

                goto the_end;

            } else {

                av_log(avctx, AV_LOG_DEBUG, "marker=%x avail_size_in_buf=%td\n", start_code, buf_end - buf_ptr);

                if ((buf_end - buf_ptr) > s->buffer_size)