ffmpeg/libavcodec/raw.c

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/*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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', '4', '2', '2') }, /* Packed formats */
{ PIX_FMT_YUV422, 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;
}
static unsigned int findFourCC(int 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);
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 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);
*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);
*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;
avctx->codec_tag = findFourCC(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);
}
AVCodec rawvideo_encoder = {
"rawvideo",
CODEC_TYPE_VIDEO,
CODEC_ID_RAWVIDEO,
sizeof(AVFrame),
raw_init_encoder,
raw_encode,
};
AVCodec rawvideo_decoder = {
"rawvideo",
CODEC_TYPE_VIDEO,
CODEC_ID_RAWVIDEO,
sizeof(RawVideoContext),
raw_init_decoder,
NULL,
raw_close_decoder,
raw_decode,
};