Subversion Repositories Kolibri OS

/*

 * Electronic Arts TGV Video Decoder

 * Copyright (c) 2007-2008 Peter Ross

 *

 * 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 St, Fifth Floor, Boston, MA  02110-1301  USA

 */

/**

 * @file

 * Electronic Arts TGV Video Decoder

 * by Peter Ross (pross@xvid.org)

 *

 * Technical details here:

 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGV

 */

#include "avcodec.h"

#define BITSTREAM_READER_LE

#include "get_bits.h"

#include "internal.h"

#include "libavutil/imgutils.h"

#include "libavutil/mem.h"

#define EA_PREAMBLE_SIZE    8

#define kVGT_TAG MKTAG('k', 'V', 'G', 'T')

typedef struct TgvContext {

    AVCodecContext *avctx;

    AVFrame *last_frame;

    uint8_t *frame_buffer;

    int width,height;

    uint32_t palette[AVPALETTE_COUNT];

    int (*mv_codebook)[2];

    uint8_t (*block_codebook)[16];

    int num_mvs;           ///< current length of mv_codebook

    int num_blocks_packed; ///< current length of block_codebook

} TgvContext;

static av_cold int tgv_decode_init(AVCodecContext *avctx)

{

    TgvContext *s = avctx->priv_data;

    s->avctx         = avctx;

    avctx->framerate = (AVRational){ 15, 1 };

    avctx->pix_fmt   = AV_PIX_FMT_PAL8;

    s->last_frame = av_frame_alloc();

    if (!s->last_frame)

        return AVERROR(ENOMEM);

    return 0;

}

/**

 * Unpack buffer

 * @return 0 on success, -1 on critical buffer underflow

 */

static int unpack(const uint8_t *src, const uint8_t *src_end,

                  uint8_t *dst, int width, int height)

{

    uint8_t *dst_end = dst + width*height;

    int size, size1, size2, offset, run;

    uint8_t *dst_start = dst;

    if (src[0] & 0x01)

        src += 5;

    else

        src += 2;

    if (src_end - src < 3)

        return AVERROR_INVALIDDATA;

    size = AV_RB24(src);

    src += 3;

    while (size > 0 && src < src_end) {

        /* determine size1 and size2 */

        size1 = (src[0] & 3);

        if (src[0] & 0x80) {  // 1

            if (src[0] & 0x40 ) {  // 11

                if (src[0] & 0x20) {  // 111

                    if (src[0] < 0xFC)  // !(111111)

                        size1 = (((src[0] & 31) + 1) << 2);

                    src++;

                    size2 = 0;

                } else {  // 110

                    offset = ((src[0] & 0x10) << 12) + AV_RB16(&src[1]) + 1;

                    size2  = ((src[0] & 0xC) << 6) + src[3] + 5;

                    src   += 4;

                }

            } else {  // 10

                size1  = ((src[1] & 0xC0) >> 6);

                offset = (AV_RB16(&src[1]) & 0x3FFF) + 1;

                size2  = (src[0] & 0x3F) + 4;

                src   += 3;

            }

        } else {  // 0

            offset = ((src[0] & 0x60) << 3) + src[1] + 1;

            size2  = ((src[0] & 0x1C) >> 2) + 3;

            src   += 2;

        }

        /* fetch strip from src */

        if (size1 > src_end - src)

            break;

        if (size1 > 0) {

            size -= size1;

            run   = FFMIN(size1, dst_end - dst);

            memcpy(dst, src, run);

            dst += run;

            src += run;

        }

        if (size2 > 0) {

            if (dst - dst_start < offset)

                return 0;

            size -= size2;

            run   = FFMIN(size2, dst_end - dst);

            av_memcpy_backptr(dst, offset, run);

            dst += run;

        }

    }

    return 0;

}

/**

 * Decode inter-frame

 * @return 0 on success, -1 on critical buffer underflow

 */

static int tgv_decode_inter(TgvContext *s, AVFrame *frame,

                            const uint8_t *buf, const uint8_t *buf_end)

{

    int num_mvs;

    int num_blocks_raw;

    int num_blocks_packed;

    int vector_bits;

    int i,j,x,y;

    GetBitContext gb;

    int mvbits;

    const uint8_t *blocks_raw;

    if(buf_end - buf < 12)

        return AVERROR_INVALIDDATA;

    num_mvs           = AV_RL16(&buf[0]);

    num_blocks_raw    = AV_RL16(&buf[2]);

    num_blocks_packed = AV_RL16(&buf[4]);

    vector_bits       = AV_RL16(&buf[6]);

    buf += 12;

    if (vector_bits > MIN_CACHE_BITS || !vector_bits) {

        av_log(s->avctx, AV_LOG_ERROR,

               "Invalid value for motion vector bits: %d\n", vector_bits);

        return AVERROR_INVALIDDATA;

    }

    /* allocate codebook buffers as necessary */

    if (num_mvs > s->num_mvs) {

        int err = av_reallocp_array(&s->mv_codebook, num_mvs, sizeof(*s->mv_codebook));

        if (err < 0) {

            s->num_mvs = 0;

            return err;

        }

        s->num_mvs = num_mvs;

    }

    if (num_blocks_packed > s->num_blocks_packed) {

        int err;

        if ((err = av_reallocp(&s->block_codebook, num_blocks_packed * 16)) < 0) {

            s->num_blocks_packed = 0;

            return err;

        }

        s->num_blocks_packed = num_blocks_packed;

    }

    /* read motion vectors */

    mvbits = (num_mvs * 2 * 10 + 31) & ~31;

    if (buf_end - buf < (mvbits>>3) + 16*num_blocks_raw + 8*num_blocks_packed)

        return AVERROR_INVALIDDATA;

    init_get_bits(&gb, buf, mvbits);

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

        s->mv_codebook[i][0] = get_sbits(&gb, 10);

        s->mv_codebook[i][1] = get_sbits(&gb, 10);

    }

    buf += mvbits >> 3;

    /* note ptr to uncompressed blocks */

    blocks_raw = buf;

    buf       += num_blocks_raw * 16;

    /* read compressed blocks */

    init_get_bits(&gb, buf, (buf_end - buf) << 3);

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

        int tmp[4];

        for (j = 0; j < 4; j++)

            tmp[j] = get_bits(&gb, 8);

        for (j = 0; j < 16; j++)

            s->block_codebook[i][15-j] = tmp[get_bits(&gb, 2)];

    }

    if (get_bits_left(&gb) < vector_bits *

        (s->avctx->height / 4) * (s->avctx->width / 4))

        return AVERROR_INVALIDDATA;

    /* read vectors and build frame */

    for (y = 0; y < s->avctx->height / 4; y++)

        for (x = 0; x < s->avctx->width / 4; x++) {

            unsigned int vector = get_bits(&gb, vector_bits);

            const uint8_t *src;

            int src_stride;

            if (vector < num_mvs) {

                int mx = x * 4 + s->mv_codebook[vector][0];

                int my = y * 4 + s->mv_codebook[vector][1];

                if (mx < 0 || mx + 4 > s->avctx->width ||

                    my < 0 || my + 4 > s->avctx->height) {

                    av_log(s->avctx, AV_LOG_ERROR, "MV %d %d out of picture\n", mx, my);

                    continue;

                }

                src = s->last_frame->data[0] + mx + my * s->last_frame->linesize[0];

                src_stride = s->last_frame->linesize[0];

            } else {

                int offset = vector - num_mvs;

                if (offset < num_blocks_raw)

                    src = blocks_raw + 16*offset;

                else if (offset - num_blocks_raw < num_blocks_packed)

                    src = s->block_codebook[offset - num_blocks_raw];

                else

                    continue;

                src_stride = 4;

            }

            for (j = 0; j < 4; j++)

                for (i = 0; i < 4; i++)

                    frame->data[0][(y * 4 + j) * frame->linesize[0] + (x * 4 + i)] =

                        src[j * src_stride + i];

    }

    return 0;

}

static int tgv_decode_frame(AVCodecContext *avctx,

                            void *data, int *got_frame,

                            AVPacket *avpkt)

{

    const uint8_t *buf     = avpkt->data;

    int buf_size           = avpkt->size;

    TgvContext *s          = avctx->priv_data;

    const uint8_t *buf_end = buf + buf_size;

    AVFrame *frame         = data;

    int chunk_type, ret;

    if (buf_end - buf < EA_PREAMBLE_SIZE)

        return AVERROR_INVALIDDATA;

    chunk_type = AV_RL32(&buf[0]);

    buf       += EA_PREAMBLE_SIZE;

    if (chunk_type == kVGT_TAG) {

        int pal_count, i;

        if(buf_end - buf < 12) {

            av_log(avctx, AV_LOG_WARNING, "truncated header\n");

            return AVERROR_INVALIDDATA;

        }

        s->width  = AV_RL16(&buf[0]);

        s->height = AV_RL16(&buf[2]);

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

            av_freep(&s->frame_buffer);

            av_frame_unref(s->last_frame);

            if ((ret = ff_set_dimensions(s->avctx, s->width, s->height)) < 0)

                return ret;

        }

        pal_count = AV_RL16(&buf[6]);

        buf += 12;

        for(i = 0; i < pal_count && i < AVPALETTE_COUNT && buf_end - buf >= 3; i++) {

            s->palette[i] = 0xFFU << 24 | AV_RB24(buf);

            buf += 3;

        }

    }

    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)

        return ret;

    memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);

    if (chunk_type == kVGT_TAG) {

        int y;

        frame->key_frame = 1;

        frame->pict_type = AV_PICTURE_TYPE_I;

        if (!s->frame_buffer &&

            !(s->frame_buffer = av_mallocz(s->width * s->height)))

            return AVERROR(ENOMEM);

        if (unpack(buf, buf_end, s->frame_buffer, s->avctx->width, s->avctx->height) < 0) {

            av_log(avctx, AV_LOG_WARNING, "truncated intra frame\n");

            return AVERROR_INVALIDDATA;

        }

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

            memcpy(frame->data[0]  + y * frame->linesize[0],

                   s->frame_buffer + y * s->width,

                   s->width);

    } else {

        if (!s->last_frame->data[0]) {

            av_log(avctx, AV_LOG_WARNING, "inter frame without corresponding intra frame\n");

            return buf_size;

        }

        frame->key_frame = 0;

        frame->pict_type = AV_PICTURE_TYPE_P;

        if (tgv_decode_inter(s, frame, buf, buf_end) < 0) {

            av_log(avctx, AV_LOG_WARNING, "truncated inter frame\n");

            return AVERROR_INVALIDDATA;

        }

    }

    av_frame_unref(s->last_frame);

    if ((ret = av_frame_ref(s->last_frame, frame)) < 0)

        return ret;

    *got_frame = 1;

    return buf_size;

}

static av_cold int tgv_decode_end(AVCodecContext *avctx)

{

    TgvContext *s = avctx->priv_data;

    av_frame_free(&s->last_frame);

    av_freep(&s->frame_buffer);

    av_freep(&s->mv_codebook);

    av_freep(&s->block_codebook);

    return 0;

}

AVCodec ff_eatgv_decoder = {

    .name           = "eatgv",

    .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts TGV video"),

    .type           = AVMEDIA_TYPE_VIDEO,

    .id             = AV_CODEC_ID_TGV,

    .priv_data_size = sizeof(TgvContext),

    .init           = tgv_decode_init,

    .close          = tgv_decode_end,

    .decode         = tgv_decode_frame,

    .capabilities   = AV_CODEC_CAP_DR1,

};