flip(avctx, picture);
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;}