libavcodec/decode.c:696: error: Uninitialized Value
  The value read from config was never initialized.

libavcodec/decode.c:696:14: 
694.                 break;
695.         }
696.         if (!config) {
                  ^
697.             // No specific config available, so the decoder must be able
698.             // to handle this format without any additional setup.

enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *avctx,
                                              const enum AVPixelFormat *fmt)
{
    const AVPixFmtDescriptor *desc;
    const AVCodecHWConfig *config;
    int i, n;
    if (avctx->hw_device_ctx && avctx->codec->hw_configs) {
        AVHWDeviceContext *device_ctx =
            (AVHWDeviceContext*)avctx->hw_device_ctx->data;
        for (i = 0;; i++) {
            config = &avctx->codec->hw_configs[i]->public;
            if (!config)
                break;
            if (!(config->methods &
                  AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX))
                continue;
            if (device_ctx->type != config->device_type)
                continue;
            for (n = 0; fmt[n] != AV_PIX_FMT_NONE; n++) {
                if (config->pix_fmt == fmt[n])
                    return fmt[n];
            }
        }
    }
    for (n = 0; fmt[n] != AV_PIX_FMT_NONE; n++);
    desc = av_pix_fmt_desc_get(fmt[n - 1]);
    if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL))
        return fmt[n - 1];
    for (n = 0; fmt[n] != AV_PIX_FMT_NONE; n++) {
        for (i = 0;; i++) {
            config = avcodec_get_hw_config(avctx->codec, i);
            if (!config)
                break;
            if (config->pix_fmt == fmt[n])
                break;
        }
        if (!config) {
            return fmt[n];
        }
        if (config->methods & AV_CODEC_HW_CONFIG_METHOD_INTERNAL) {
            return fmt[n];
        }
    }
    return AV_PIX_FMT_NONE;
}
['enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *avctx,\n                                              const enum AVPixelFormat *fmt)\n{\n    const AVPixFmtDescriptor *desc;\n    const AVCodecHWConfig *config;\n    int i, n;\n    if (avctx->hw_device_ctx && avctx->codec->hw_configs) {\n        AVHWDeviceContext *device_ctx =\n            (AVHWDeviceContext*)avctx->hw_device_ctx->data;\n        for (i = 0;; i++) {\n            config = &avctx->codec->hw_configs[i]->public;\n            if (!config)\n                break;\n            if (!(config->methods &\n                  AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX))\n                continue;\n            if (device_ctx->type != config->device_type)\n                continue;\n            for (n = 0; fmt[n] != AV_PIX_FMT_NONE; n++) {\n                if (config->pix_fmt == fmt[n])\n                    return fmt[n];\n            }\n        }\n    }\n    for (n = 0; fmt[n] != AV_PIX_FMT_NONE; n++);\n    desc = av_pix_fmt_desc_get(fmt[n - 1]);\n    if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL))\n        return fmt[n - 1];\n    for (n = 0; fmt[n] != AV_PIX_FMT_NONE; n++) {\n        for (i = 0;; i++) {\n            config = avcodec_get_hw_config(avctx->codec, i);\n            if (!config)\n                break;\n            if (config->pix_fmt == fmt[n])\n                break;\n        }\n        if (!config) {\n            return fmt[n];\n        }\n        if (config->methods & AV_CODEC_HW_CONFIG_METHOD_INTERNAL) {\n            return fmt[n];\n        }\n    }\n    return AV_PIX_FMT_NONE;\n}']