PeerStreamer

/*

 * V.Flash PTX (.ptx) image decoder

 * Copyright (c) 2007 Ivo van Poorten

 *

 * 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

 */

#include "libavutil/intreadwrite.h"

#include "libavutil/imgutils.h"

#include "avcodec.h"

typedef struct PTXContext {

    AVFrame picture;

} PTXContext;

static av_cold int ptx_init(AVCodecContext *avctx) {

    PTXContext *s = avctx->priv_data;

    avcodec_get_frame_defaults(&s->picture);

    avctx->coded_frame= &s->picture;

    return 0;

}

static int ptx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,

                            AVPacket *avpkt) {

    const uint8_t *buf = avpkt->data;

    PTXContext * const s = avctx->priv_data;

    AVFrame *picture = data;

    AVFrame * const p = &s->picture;

    unsigned int offset, w, h, y, stride, bytes_per_pixel;

    uint8_t *ptr;

    offset          = AV_RL16(buf);

    w               = AV_RL16(buf+8);

    h               = AV_RL16(buf+10);

    bytes_per_pixel = AV_RL16(buf+12) >> 3;

    if (bytes_per_pixel != 2) {

        av_log_ask_for_sample(avctx, "Image format is not RGB15.\n");

        return -1;

    }

    avctx->pix_fmt = PIX_FMT_RGB555;

    if (offset != 0x2c)

        av_log_ask_for_sample(avctx, "offset != 0x2c\n");

    buf += offset;

    if (p->data[0])

        avctx->release_buffer(avctx, p);

    if (av_image_check_size(w, h, 0, avctx))

        return -1;

    if (w != avctx->width || h != avctx->height)

        avcodec_set_dimensions(avctx, w, h);

    if (avctx->get_buffer(avctx, p) < 0) {

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

        return -1;

    }

    p->pict_type = AV_PICTURE_TYPE_I;

    ptr    = p->data[0];

    stride = p->linesize[0];

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

#if HAVE_BIGENDIAN

        unsigned int x;

        for (x=0; x<w*bytes_per_pixel; x+=bytes_per_pixel)

            AV_WN16(ptr+x, AV_RL16(buf+x));

#else

        memcpy(ptr, buf, w*bytes_per_pixel);

#endif

        ptr += stride;

        buf += w*bytes_per_pixel;

    }

    *picture = s->picture;

    *data_size = sizeof(AVPicture);

    return offset + w*h*bytes_per_pixel;

}

static av_cold int ptx_end(AVCodecContext *avctx) {

    PTXContext *s = avctx->priv_data;

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

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

    return 0;

}

AVCodec ff_ptx_decoder = {

    "ptx",

    AVMEDIA_TYPE_VIDEO,

    CODEC_ID_PTX,

    sizeof(PTXContext),

    ptx_init,

    NULL,

    ptx_end,

    ptx_decode_frame,

    CODEC_CAP_DR1,

    NULL,

    .long_name = NULL_IF_CONFIG_SMALL("V.Flash PTX image"),

};