Function avcodec_copy_context

libavcodec/options.c:474–530

}

int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src)
{
    if (dest->codec) { // check that the dest context is uninitialized
        av_log(dest, AV_LOG_ERROR,
               "Tried to copy AVCodecContext %p into already-initialized %p\n",
               src, dest);
        return AVERROR(EINVAL);
    }
    memcpy(dest, src, sizeof(*dest));

    /* set values specific to opened codecs back to their default state */
    dest->priv_data       = NULL;
    dest->codec           = NULL;
    dest->palctrl         = NULL;
    dest->slice_offset    = NULL;
    dest->internal_buffer = NULL;
    dest->hwaccel         = NULL;
    dest->thread_opaque   = NULL;

    /* reallocate values that should be allocated separately */
    dest->rc_eq           = NULL;
    dest->extradata       = NULL;
    dest->intra_matrix    = NULL;
    dest->inter_matrix    = NULL;
    dest->rc_override     = NULL;
    if (src->rc_eq) {
        dest->rc_eq = av_strdup(src->rc_eq);
        if (!dest->rc_eq)
            return AVERROR(ENOMEM);
    }

#define alloc_and_copy_or_fail(obj, size, pad) \
    if (src->obj && size > 0) { \
        dest->obj = av_malloc(size + pad); \
        if (!dest->obj) \
            goto fail; \
        memcpy(dest->obj, src->obj, size); \
        if (pad) \
            memset(((uint8_t *) dest->obj) + size, 0, pad); \
    }
    alloc_and_copy_or_fail(extradata,    src->extradata_size,
                           FF_INPUT_BUFFER_PADDING_SIZE);
    alloc_and_copy_or_fail(intra_matrix, 64 * sizeof(int16_t), 0);
    alloc_and_copy_or_fail(inter_matrix, 64 * sizeof(int16_t), 0);
    alloc_and_copy_or_fail(rc_override,  src->rc_override_count * sizeof(*src->rc_override), 0);
#undef alloc_and_copy_or_fail

    return 0;

fail:
    av_freep(&dest->rc_override);
    av_freep(&dest->intra_matrix);
    av_freep(&dest->inter_matrix);
    av_freep(&dest->extradata);
    av_freep(&dest->rc_eq);
    return AVERROR(ENOMEM);
}