PeerStreamer

/*

 * Raw Video Codec

 * Copyright (c) 2001 Fabrice Bellard.

 *

 * 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 raw.c

 * Raw Video Codec

 */

#include "avcodec.h"

typedef struct RawVideoContext {

    unsigned char * buffer;  /* block of memory for holding one frame */

    unsigned char * p;       /* current position in buffer */

    int             length;  /* number of bytes in buffer */

    AVFrame pic;             ///< AVCodecContext.coded_frame

} RawVideoContext;

typedef struct PixleFormatTag {

    int pix_fmt;

    unsigned int fourcc;

} PixelFormatTag;

const PixelFormatTag pixelFormatTags[] = {

    { PIX_FMT_YUV420P, MKTAG('I', '4', '2', '0') }, /* Planar formats */

    { PIX_FMT_YUV420P, MKTAG('I', 'Y', 'U', 'V') },

    { PIX_FMT_YUV410P, MKTAG('Y', 'U', 'V', '9') },

    { PIX_FMT_YUV411P, MKTAG('Y', '4', '1', 'B') },

    { PIX_FMT_YUV422P, MKTAG('Y', '4', '2', 'B') },

    { PIX_FMT_GRAY8,   MKTAG('Y', '8', '0', '0') },

    { PIX_FMT_GRAY8,   MKTAG(' ', ' ', 'Y', '8') },

    { PIX_FMT_YUV422,  MKTAG('Y', 'U', 'Y', '2') }, /* Packed formats */

    { PIX_FMT_YUV422,  MKTAG('Y', '4', '2', '2') },

    { PIX_FMT_UYVY422, MKTAG('U', 'Y', 'V', 'Y') },

    { PIX_FMT_GRAY8,   MKTAG('G', 'R', 'E', 'Y') },

    { -1, 0 },

};

static int findPixelFormat(unsigned int fourcc)

{

    const PixelFormatTag * tags = pixelFormatTags;

    while (tags->pix_fmt >= 0) {

        if (tags->fourcc == fourcc)

            return tags->pix_fmt;

        tags++;

    }

    return PIX_FMT_YUV420P;

}

unsigned int avcodec_pix_fmt_to_codec_tag(enum PixelFormat fmt)

{

    const PixelFormatTag * tags = pixelFormatTags;

    while (tags->pix_fmt >= 0) {

        if (tags->pix_fmt == fmt)

            return tags->fourcc;

        tags++;

    }

    return 0;

}

/* RAW Decoder Implementation */

static int raw_init_decoder(AVCodecContext *avctx)

{

    RawVideoContext *context = avctx->priv_data;

    if (avctx->codec_tag)

        avctx->pix_fmt = findPixelFormat(avctx->codec_tag);

    else if (avctx->bits_per_sample){

        switch(avctx->bits_per_sample){

        case 15: avctx->pix_fmt= PIX_FMT_RGB555; break;

        case 16: avctx->pix_fmt= PIX_FMT_RGB565; break;

        case 24: avctx->pix_fmt= PIX_FMT_BGR24 ; break;

        case 32: avctx->pix_fmt= PIX_FMT_RGBA32; break;

        }

    }

    context->length = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);

    context->buffer = av_malloc(context->length);

    context->p      = context->buffer;

    context->pic.pict_type = FF_I_TYPE;

    context->pic.key_frame = 1;

    avctx->coded_frame= &context->pic;

    if (!context->buffer)

        return -1;

    return 0;

}

static void flip(AVCodecContext *avctx, AVPicture * picture){

    if(!avctx->codec_tag && avctx->bits_per_sample && picture->linesize[1]==0){

        picture->data[0] += picture->linesize[0] * (avctx->height-1);

        picture->linesize[0] *= -1;

    }

}

static int raw_decode(AVCodecContext *avctx,

                            void *data, int *data_size,

                            uint8_t *buf, int buf_size)

{

    RawVideoContext *context = avctx->priv_data;

    int bytesNeeded;

    AVPicture * picture = (AVPicture *) data;

    /* Early out without copy if packet size == frame size */

    if (buf_size == context->length  &&  context->p == context->buffer) {

        avpicture_fill(picture, buf, avctx->pix_fmt, avctx->width, avctx->height);

        flip(avctx, picture);

        *data_size = sizeof(AVPicture);

        return buf_size;

    }

    bytesNeeded = context->length - (context->p - context->buffer);

    if (buf_size < bytesNeeded) {

        memcpy(context->p, buf, buf_size);

        context->p += buf_size;

        return buf_size;

    }

    memcpy(context->p, buf, bytesNeeded);

    context->p = context->buffer;

    avpicture_fill(picture, context->buffer, avctx->pix_fmt, avctx->width, avctx->height);

    flip(avctx, picture);

    *data_size = sizeof(AVPicture);

    return bytesNeeded;

}

static int raw_close_decoder(AVCodecContext *avctx)

{

    RawVideoContext *context = avctx->priv_data;

    av_freep(&context->buffer);

    return 0;

}

/* RAW Encoder Implementation */

static int raw_init_encoder(AVCodecContext *avctx)

{

    avctx->coded_frame = (AVFrame *)avctx->priv_data;

    avctx->coded_frame->pict_type = FF_I_TYPE;

    avctx->coded_frame->key_frame = 1;

    if(!avctx->codec_tag)

        avctx->codec_tag = avcodec_pix_fmt_to_codec_tag(avctx->pix_fmt);

    return 0;

}

static int raw_encode(AVCodecContext *avctx,

                            unsigned char *frame, int buf_size, void *data)

{

    return avpicture_layout((AVPicture *)data, avctx->pix_fmt, avctx->width,

                                               avctx->height, frame, buf_size);

}

#ifdef CONFIG_RAWVIDEO_ENCODER

AVCodec rawvideo_encoder = {

    "rawvideo",

    CODEC_TYPE_VIDEO,

    CODEC_ID_RAWVIDEO,

    sizeof(AVFrame),

    raw_init_encoder,

    raw_encode,

};

#endif // CONFIG_RAWVIDEO_ENCODER

AVCodec rawvideo_decoder = {

    "rawvideo",

    CODEC_TYPE_VIDEO,

    CODEC_ID_RAWVIDEO,

    sizeof(RawVideoContext),

    raw_init_decoder,

    NULL,

    raw_close_decoder,

    raw_decode,

};