PeerStreamer

/*

 * Forward Uncompressed

 *

 * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>

 *

 * 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 "avcodec.h"

#include "bytestream.h"

#include "libavutil/intreadwrite.h"

static av_cold int decode_init(AVCodecContext *avctx)

{

    if (avctx->width & 1) {

        av_log(avctx, AV_LOG_ERROR, "frwu needs even width\n");

        return -1;

    }

    avctx->pix_fmt = PIX_FMT_UYVY422;

    avctx->coded_frame = avcodec_alloc_frame();

    return 0;

}

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

                        AVPacket *avpkt)

{

    int field;

    AVFrame *pic = avctx->coded_frame;

    const uint8_t *buf = avpkt->data;

    const uint8_t *buf_end = buf + avpkt->size;

    if (pic->data[0])

        avctx->release_buffer(avctx, pic);

    if (avpkt->size < avctx->width * 2 * avctx->height + 4 + 2*8) {

        av_log(avctx, AV_LOG_ERROR, "Packet is too small.\n");

        return -1;

    }

    if (bytestream_get_le32(&buf) != AV_RL32("FRW1")) {

        av_log(avctx, AV_LOG_ERROR, "incorrect marker\n");

        return -1;

    }

    pic->reference = 0;

    if (avctx->get_buffer(avctx, pic) < 0)

        return -1;

    pic->pict_type = AV_PICTURE_TYPE_I;

    pic->key_frame = 1;

    pic->interlaced_frame = 1;

    pic->top_field_first = 1;

    for (field = 0; field < 2; field++) {

        int i;

        int field_h = (avctx->height + !field) >> 1;

        int field_size, min_field_size = avctx->width * 2 * field_h;

        uint8_t *dst = pic->data[0];

        if (buf_end - buf < 8)

            return -1;

        buf += 4; // flags? 0x80 == bottom field maybe?

        field_size = bytestream_get_le32(&buf);

        if (field_size < min_field_size) {

            av_log(avctx, AV_LOG_ERROR, "Field size %i is too small (required %i)\n", field_size, min_field_size);

            return -1;

        }

        if (buf_end - buf < field_size) {

            av_log(avctx, AV_LOG_ERROR, "Packet is too small, need %i, have %i\n", field_size, (int)(buf_end - buf));

            return -1;

        }

        if (field)

            dst += pic->linesize[0];

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

            memcpy(dst, buf, avctx->width * 2);

            buf += avctx->width * 2;

            dst += pic->linesize[0] << 1;

        }

        buf += field_size - min_field_size;

    }

    *data_size = sizeof(AVFrame);

    *(AVFrame*)data = *pic;

    return avpkt->size;

}

static av_cold int decode_close(AVCodecContext *avctx)

{

    AVFrame *pic = avctx->coded_frame;

    if (pic->data[0])

        avctx->release_buffer(avctx, pic);

    av_freep(&avctx->coded_frame);

    return 0;

}

AVCodec ff_frwu_decoder = {

    "frwu",

    AVMEDIA_TYPE_VIDEO,

    CODEC_ID_FRWU,

    0,

    decode_init,

    NULL,

    decode_close,

    decode_frame,

    CODEC_CAP_DR1,

    .long_name = NULL_IF_CONFIG_SMALL("Forward Uncompressed"),

};