int av_buffer_realloc(AVBufferRef **pbuf, int size)
{
    AVBufferRef *buf = *pbuf;
    uint8_t *tmp;
    if (!buf) {
        uint8_t *data = av_realloc(NULL, size);
        if (!data)
            return AVERROR(ENOMEM);
        buf = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);
        if (!buf) {
            av_freep(&data);
            return AVERROR(ENOMEM);
        }
        buf->buffer->flags |= BUFFER_FLAG_REALLOCATABLE;
        *pbuf = buf;
        return 0;
    } else if (buf->size == size)
        return 0;
    if (!(buf->buffer->flags & BUFFER_FLAG_REALLOCATABLE) ||
        !av_buffer_is_writable(buf)) {
        AVBufferRef *new = NULL;
        av_buffer_realloc(&new, size);
        if (!new)
            return AVERROR(ENOMEM);
        memcpy(new->data, buf->data, FFMIN(size, buf->size));
        av_buffer_unref(pbuf);
        *pbuf = new;
        return 0;
    }
    tmp = av_realloc(buf->buffer->data, size);
    if (!tmp)
        return AVERROR(ENOMEM);
    buf->buffer->data = buf->data = tmp;
    buf->buffer->size = buf->size = size;
    return 0;
}
['int av_buffer_realloc(AVBufferRef **pbuf, int size)\n{\n    AVBufferRef *buf = *pbuf;\n    uint8_t *tmp;\n    if (!buf) {\n        uint8_t *data = av_realloc(NULL, size);\n        if (!data)\n            return AVERROR(ENOMEM);\n        buf = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);\n        if (!buf) {\n            av_freep(&data);\n            return AVERROR(ENOMEM);\n        }\n        buf->buffer->flags |= BUFFER_FLAG_REALLOCATABLE;\n        *pbuf = buf;\n        return 0;\n    } else if (buf->size == size)\n        return 0;\n    if (!(buf->buffer->flags & BUFFER_FLAG_REALLOCATABLE) ||\n        !av_buffer_is_writable(buf)) {\n        AVBufferRef *new = NULL;\n        av_buffer_realloc(&new, size);\n        if (!new)\n            return AVERROR(ENOMEM);\n        memcpy(new->data, buf->data, FFMIN(size, buf->size));\n        av_buffer_unref(pbuf);\n        *pbuf = new;\n        return 0;\n    }\n    tmp = av_realloc(buf->buffer->data, size);\n    if (!tmp)\n        return AVERROR(ENOMEM);\n    buf->buffer->data = buf->data = tmp;\n    buf->buffer->size = buf->size = size;\n    return 0;\n}', 'void *av_realloc(void *ptr, size_t size)\n{\n#if CONFIG_MEMALIGN_HACK\n    int diff;\n#endif\n    if (size > (INT_MAX - 16))\n        return NULL;\n#if CONFIG_MEMALIGN_HACK\n    if (!ptr)\n        return av_malloc(size);\n    diff = ((char *)ptr)[-1];\n    return (char *)realloc((char *)ptr - diff, size + diff) + diff;\n#elif HAVE_ALIGNED_MALLOC\n    return _aligned_realloc(ptr, size, 32);\n#else\n    return realloc(ptr, size);\n#endif\n}']