PeerStreamer

/*

 * Fraps FPS1 decoder

 * Copyright (c) 2005 Roine Gustafsson

 * Copyright (c) 2006 Konstantin Shishkov

 *

 * 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

 * Lossless Fraps 'FPS1' decoder

 * @author Roine Gustafsson (roine at users sf net)

 * @author Konstantin Shishkov

 *

 * Codec algorithm for version 0 is taken from Transcode <www.transcoding.org>

 *

 * Version 2 files support by Konstantin Shishkov

 */

#include "avcodec.h"

#include "get_bits.h"

#include "huffman.h"

#include "bytestream.h"

#include "dsputil.h"

#define FPS_TAG MKTAG('F', 'P', 'S', 'x')

/**

 * local variable storage

 */

typedef struct FrapsContext{

    AVCodecContext *avctx;

    AVFrame frame;

    uint8_t *tmpbuf;

    DSPContext dsp;

} FrapsContext;

/**

 * initializes decoder

 * @param avctx codec context

 * @return 0 on success or negative if fails

 */

static av_cold int decode_init(AVCodecContext *avctx)

{

    FrapsContext * const s = avctx->priv_data;

    avctx->coded_frame = (AVFrame*)&s->frame;

    avctx->pix_fmt= PIX_FMT_NONE; /* set in decode_frame */

    s->avctx = avctx;

    s->tmpbuf = NULL;

    dsputil_init(&s->dsp, avctx);

    return 0;

}

/**

 * Comparator - our nodes should ascend by count

 * but with preserved symbol order

 */

static int huff_cmp(const void *va, const void *vb){

    const Node *a = va, *b = vb;

    return (a->count - b->count)*256 + a->sym - b->sym;

}

/**

 * decode Fraps v2 packed plane

 */

static int fraps2_decode_plane(FrapsContext *s, uint8_t *dst, int stride, int w,

                               int h, const uint8_t *src, int size, int Uoff,

                               const int step)

{

    int i, j;

    GetBitContext gb;

    VLC vlc;

    Node nodes[512];

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

        nodes[i].count = bytestream_get_le32(&src);

    size -= 1024;

    if (ff_huff_build_tree(s->avctx, &vlc, 256, nodes, huff_cmp,

                           FF_HUFFMAN_FLAG_ZERO_COUNT) < 0)

        return -1;

    /* we have built Huffman table and are ready to decode plane */

    /* convert bits so they may be used by standard bitreader */

    s->dsp.bswap_buf((uint32_t *)s->tmpbuf, (const uint32_t *)src, size >> 2);

    init_get_bits(&gb, s->tmpbuf, size * 8);

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

        for(i = 0; i < w*step; i += step){

            dst[i] = get_vlc2(&gb, vlc.table, 9, 3);

            /* lines are stored as deltas between previous lines

             * and we need to add 0x80 to the first lines of chroma planes

             */

            if(j) dst[i] += dst[i - stride];

            else if(Uoff) dst[i] += 0x80;

        }

        dst += stride;

    }

    free_vlc(&vlc);

    return 0;

}

static int decode_frame(AVCodecContext *avctx,

                        void *data, int *data_size,

                        AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    FrapsContext * const s = avctx->priv_data;

    AVFrame *frame = data;

    AVFrame * const f = (AVFrame*)&s->frame;

    uint32_t header;

    unsigned int version,header_size;

    unsigned int x, y;

    const uint32_t *buf32;

    uint32_t *luma1,*luma2,*cb,*cr;

    uint32_t offs[4];

    int i, j, is_chroma, planes;

    header = AV_RL32(buf);

    version = header & 0xff;

    header_size = (header & (1<<30))? 8 : 4; /* bit 30 means pad to 8 bytes */

    if (version > 5) {

        av_log(avctx, AV_LOG_ERROR,

               "This file is encoded with Fraps version %d. " \

               "This codec can only decode versions <= 5.\n", version);

        return -1;

    }

    buf+=4;

    if (header_size == 8)

        buf+=4;

    switch(version) {

    case 0:

    default:

        /* Fraps v0 is a reordered YUV420 */

        avctx->pix_fmt = PIX_FMT_YUV420P;

        if ( (buf_size != avctx->width*avctx->height*3/2+header_size) &&

             (buf_size != header_size) ) {

            av_log(avctx, AV_LOG_ERROR,

                   "Invalid frame length %d (should be %d)\n",

                   buf_size, avctx->width*avctx->height*3/2+header_size);

            return -1;

        }

        if (( (avctx->width % 8) != 0) || ( (avctx->height % 2) != 0 )) {

            av_log(avctx, AV_LOG_ERROR, "Invalid frame size %dx%d\n",

                   avctx->width, avctx->height);

            return -1;

        }

        f->reference = 1;

        f->buffer_hints = FF_BUFFER_HINTS_VALID |

                          FF_BUFFER_HINTS_PRESERVE |

                          FF_BUFFER_HINTS_REUSABLE;

        if (avctx->reget_buffer(avctx, f)) {

            av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");

            return -1;

        }

        /* bit 31 means same as previous pic */

        f->pict_type = (header & (1<<31))? FF_P_TYPE : FF_I_TYPE;

        f->key_frame = f->pict_type == FF_I_TYPE;

        if (f->pict_type == FF_I_TYPE) {

            buf32=(const uint32_t*)buf;

            for(y=0; y<avctx->height/2; y++){

                luma1=(uint32_t*)&f->data[0][ y*2*f->linesize[0] ];

                luma2=(uint32_t*)&f->data[0][ (y*2+1)*f->linesize[0] ];

                cr=(uint32_t*)&f->data[1][ y*f->linesize[1] ];

                cb=(uint32_t*)&f->data[2][ y*f->linesize[2] ];

                for(x=0; x<avctx->width; x+=8){

                    *(luma1++) = *(buf32++);

                    *(luma1++) = *(buf32++);

                    *(luma2++) = *(buf32++);

                    *(luma2++) = *(buf32++);

                    *(cr++) = *(buf32++);

                    *(cb++) = *(buf32++);

                }

            }

        }

        break;

    case 1:

        /* Fraps v1 is an upside-down BGR24 */

        avctx->pix_fmt = PIX_FMT_BGR24;

        if ( (buf_size != avctx->width*avctx->height*3+header_size) &&

             (buf_size != header_size) ) {

            av_log(avctx, AV_LOG_ERROR,

                   "Invalid frame length %d (should be %d)\n",

                   buf_size, avctx->width*avctx->height*3+header_size);

            return -1;

        }

        f->reference = 1;

        f->buffer_hints = FF_BUFFER_HINTS_VALID |

                          FF_BUFFER_HINTS_PRESERVE |

                          FF_BUFFER_HINTS_REUSABLE;

        if (avctx->reget_buffer(avctx, f)) {

            av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");

            return -1;

        }

        /* bit 31 means same as previous pic */

        f->pict_type = (header & (1<<31))? FF_P_TYPE : FF_I_TYPE;

        f->key_frame = f->pict_type == FF_I_TYPE;

        if (f->pict_type == FF_I_TYPE) {

            for(y=0; y<avctx->height; y++)

                memcpy(&f->data[0][ (avctx->height-y)*f->linesize[0] ],

                       &buf[y*avctx->width*3],

                       3*avctx->width);

        }

        break;

    case 2:

    case 4:

        /**

         * Fraps v2 is Huffman-coded YUV420 planes

         * Fraps v4 is virtually the same

         */

        avctx->pix_fmt = PIX_FMT_YUV420P;

        planes = 3;

        f->reference = 1;

        f->buffer_hints = FF_BUFFER_HINTS_VALID |

                          FF_BUFFER_HINTS_PRESERVE |

                          FF_BUFFER_HINTS_REUSABLE;

        if (avctx->reget_buffer(avctx, f)) {

            av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");

            return -1;

        }

        /* skip frame */

        if(buf_size == 8) {

            f->pict_type = FF_P_TYPE;

            f->key_frame = 0;

            break;

        }

        f->pict_type = FF_I_TYPE;

        f->key_frame = 1;

        if ((AV_RL32(buf) != FPS_TAG)||(buf_size < (planes*1024 + 24))) {

            av_log(avctx, AV_LOG_ERROR, "Fraps: error in data stream\n");

            return -1;

        }

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

            offs[i] = AV_RL32(buf + 4 + i * 4);

            if(offs[i] >= buf_size || (i && offs[i] <= offs[i - 1] + 1024)) {

                av_log(avctx, AV_LOG_ERROR, "Fraps: plane %i offset is out of bounds\n", i);

                return -1;

            }

        }

        offs[planes] = buf_size;

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

            is_chroma = !!i;

            s->tmpbuf = av_realloc(s->tmpbuf, offs[i + 1] - offs[i] - 1024 + FF_INPUT_BUFFER_PADDING_SIZE);

            if(fraps2_decode_plane(s, f->data[i], f->linesize[i], avctx->width >> is_chroma,

                    avctx->height >> is_chroma, buf + offs[i], offs[i + 1] - offs[i], is_chroma, 1) < 0) {

                av_log(avctx, AV_LOG_ERROR, "Error decoding plane %i\n", i);

                return -1;

            }

        }

        break;

    case 3:

    case 5:

        /* Virtually the same as version 4, but is for RGB24 */

        avctx->pix_fmt = PIX_FMT_BGR24;

        planes = 3;

        f->reference = 1;

        f->buffer_hints = FF_BUFFER_HINTS_VALID |

                          FF_BUFFER_HINTS_PRESERVE |

                          FF_BUFFER_HINTS_REUSABLE;

        if (avctx->reget_buffer(avctx, f)) {

            av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");

            return -1;

        }

        /* skip frame */

        if(buf_size == 8) {

            f->pict_type = FF_P_TYPE;

            f->key_frame = 0;

            break;

        }

        f->pict_type = FF_I_TYPE;

        f->key_frame = 1;

        if ((AV_RL32(buf) != FPS_TAG)||(buf_size < (planes*1024 + 24))) {

            av_log(avctx, AV_LOG_ERROR, "Fraps: error in data stream\n");

            return -1;

        }

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

            offs[i] = AV_RL32(buf + 4 + i * 4);

            if(offs[i] >= buf_size || (i && offs[i] <= offs[i - 1] + 1024)) {

                av_log(avctx, AV_LOG_ERROR, "Fraps: plane %i offset is out of bounds\n", i);

                return -1;

            }

        }

        offs[planes] = buf_size;

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

            s->tmpbuf = av_realloc(s->tmpbuf, offs[i + 1] - offs[i] - 1024 + FF_INPUT_BUFFER_PADDING_SIZE);

            if(fraps2_decode_plane(s, f->data[0] + i + (f->linesize[0] * (avctx->height - 1)), -f->linesize[0],

                    avctx->width, avctx->height, buf + offs[i], offs[i + 1] - offs[i], 0, 3) < 0) {

                av_log(avctx, AV_LOG_ERROR, "Error decoding plane %i\n", i);

                return -1;

            }

        }

        // convert pseudo-YUV into real RGB

        for(j = 0; j < avctx->height; j++){

            for(i = 0; i < avctx->width; i++){

                f->data[0][0 + i*3 + j*f->linesize[0]] += f->data[0][1 + i*3 + j*f->linesize[0]];

                f->data[0][2 + i*3 + j*f->linesize[0]] += f->data[0][1 + i*3 + j*f->linesize[0]];

            }

        }

        break;

    }

    *frame = *f;

    *data_size = sizeof(AVFrame);

    return buf_size;

}

/**

 * closes decoder

 * @param avctx codec context

 * @return 0 on success or negative if fails

 */

static av_cold int decode_end(AVCodecContext *avctx)

{

    FrapsContext *s = (FrapsContext*)avctx->priv_data;

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

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

    av_freep(&s->tmpbuf);

    return 0;

}

AVCodec fraps_decoder = {

    "fraps",

    AVMEDIA_TYPE_VIDEO,

    CODEC_ID_FRAPS,

    sizeof(FrapsContext),

    decode_init,

    NULL,

    decode_end,

    decode_frame,

    CODEC_CAP_DR1,

    .long_name = NULL_IF_CONFIG_SMALL("Fraps"),

};