PeerStreamer

/*

 * Quicktime Planar RGB (8BPS) Video Decoder

 * Copyright (C) 2003 Roberto Togni

 *

 * This library 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 of the License, or (at your option) any later version.

 *

 * This library 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 this library; if not, write to the Free Software

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

 *

 */

/**

 * @file 8bps.c

 * QT 8BPS Video Decoder by Roberto Togni <rtogni at bresciaonline dot it>

 * For more information about the 8BPS format, visit:

 *   http://www.pcisys.net/~melanson/codecs/

 *

 * Supports: PAL8 (RGB 8bpp, paletted)

 *         : BGR24 (RGB 24bpp) (can also output it as RGBA32)

 *         : RGBA32 (RGB 32bpp, 4th plane is probably alpha and it's ignored)

 *

 */

#include <stdio.h>

#include <stdlib.h>

#include "common.h"

#include "avcodec.h"

const enum PixelFormat pixfmt_rgb24[] = {PIX_FMT_BGR24, PIX_FMT_RGBA32, -1};

/*

 * Decoder context

 */

typedef struct EightBpsContext {

        AVCodecContext *avctx;

        AVFrame pic;

        unsigned char planes;

        unsigned char planemap[4];

} EightBpsContext;

/*

 *

 * Decode a frame

 *

 */

static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)

{

        EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;

        unsigned char *encoded = (unsigned char *)buf;

        unsigned char *pixptr, *pixptr_end;

        unsigned int height = avctx->height; // Real image height

        unsigned int dlen, p, row;

        unsigned char *lp, *dp;

        unsigned char count;

        unsigned int px_inc;

        unsigned int planes = c->planes;

        unsigned char *planemap = c->planemap;

        if(c->pic.data[0])

                avctx->release_buffer(avctx, &c->pic);

        c->pic.reference = 0;

        c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;

        if(avctx->get_buffer(avctx, &c->pic) < 0){

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

                return -1;

        }

        /* Set data pointer after line lengths */

        dp = encoded + planes * (height << 1);

        /* Ignore alpha plane, don't know what to do with it */

        if (planes == 4)

                planes--;

        px_inc = planes + (avctx->pix_fmt == PIX_FMT_RGBA32);

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

                /* Lines length pointer for this plane */

                lp = encoded + p * (height << 1);

                /* Decode a plane */

                for(row = 0; row < height; row++) {

                        pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];

                        pixptr_end = pixptr + c->pic.linesize[0];

                        dlen = be2me_16(*(unsigned short *)(lp+row*2));

                        /* Decode a row of this plane */

                        while(dlen > 0) {

                                if(dp + 1 >= buf+buf_size) return -1;

                                if ((count = *dp++) <= 127) {

                                        count++;

                                        dlen -= count + 1;

                                        if (pixptr + count * px_inc > pixptr_end)

                                            break;

                                        if(dp + count > buf+buf_size) return -1;

                                        while(count--) {

                                                *pixptr = *dp++;

                                                pixptr += px_inc;

                                        }

                                } else {

                                        count = 257 - count;

                                        if (pixptr + count * px_inc > pixptr_end)

                                            break;

                                        while(count--) {

                                                *pixptr = *dp;

                                                pixptr += px_inc;

                                        }

                                        dp++;

                                        dlen -= 2;

                                }

                        }

                }

        }

        if (avctx->palctrl) {

                memcpy (c->pic.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);

                if (avctx->palctrl->palette_changed) {

                        c->pic.palette_has_changed = 1;

                        avctx->palctrl->palette_changed = 0;

                } else

                        c->pic.palette_has_changed = 0;

        }

        *data_size = sizeof(AVFrame);

        *(AVFrame*)data = c->pic;

        /* always report that the buffer was completely consumed */

        return buf_size;

}

/*

 *

 * Init 8BPS decoder

 *

 */

static int decode_init(AVCodecContext *avctx)

{

        EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;

        c->avctx = avctx;

        avctx->has_b_frames = 0;

        c->pic.data[0] = NULL;

    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {

        return 1;

    }

        switch (avctx->bits_per_sample) {

                case 8:

                        avctx->pix_fmt = PIX_FMT_PAL8;

                        c->planes = 1;

                        c->planemap[0] = 0; // 1st plane is palette indexes

                        if (avctx->palctrl == NULL) {

                                av_log(avctx, AV_LOG_ERROR, "Error: PAL8 format but no palette from demuxer.\n");

                                return -1;

                        }

                        break;

                case 24:

                        avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);

                        c->planes = 3;

                        c->planemap[0] = 2; // 1st plane is red

                        c->planemap[1] = 1; // 2nd plane is green

                        c->planemap[2] = 0; // 3rd plane is blue

                        break;

                case 32:

                        avctx->pix_fmt = PIX_FMT_RGBA32;

                        c->planes = 4;

#ifdef WORDS_BIGENDIAN

                        c->planemap[0] = 1; // 1st plane is red

                        c->planemap[1] = 2; // 2nd plane is green

                        c->planemap[2] = 3; // 3rd plane is blue

                        c->planemap[3] = 0; // 4th plane is alpha???

#else

                        c->planemap[0] = 2; // 1st plane is red

                        c->planemap[1] = 1; // 2nd plane is green

                        c->planemap[2] = 0; // 3rd plane is blue

                        c->planemap[3] = 3; // 4th plane is alpha???

#endif

                        break;

                default:

                        av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_sample);

                        return -1;

        }

  return 0;

}

/*

 *

 * Uninit 8BPS decoder

 *

 */

static int decode_end(AVCodecContext *avctx)

{

        EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;

        if (c->pic.data[0])

                avctx->release_buffer(avctx, &c->pic);

        return 0;

}

AVCodec eightbps_decoder = {

        "8bps",

        CODEC_TYPE_VIDEO,

        CODEC_ID_8BPS,

        sizeof(EightBpsContext),

        decode_init,

        NULL,

        decode_end,

        decode_frame,

        CODEC_CAP_DR1,

};