libavfilter/af_channelmap.c:368: error: Integer Overflow L2
  ([0, 126] - 1):unsigned64 by call to `av_get_channel_layout_channel_index`.

libavfilter/af_channelmap.c:368:33: Call
366. 
367.         if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {
368.             m->in_channel_idx = av_get_channel_layout_channel_index(
                                     ^
369.                 inlink->channel_layout, m->in_channel);
370.         }

libavutil/channel_layout.c:203:9: Assignment
  201.     if (!(channel_layout & channel) ||
  202.         av_get_channel_layout_nb_channels(channel) != 1)
  203.         return AVERROR(EINVAL);
               ^
  204.     channel_layout &= channel - 1;
  205.     return av_get_channel_layout_nb_channels(channel_layout);

libavfilter/af_channelmap.c:368:13: Assignment
366. 
367.         if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {
368.             m->in_channel_idx = av_get_channel_layout_channel_index(
                 ^
369.                 inlink->channel_layout, m->in_channel);
370.         }

libavfilter/af_channelmap.c:368:33: Call
366. 
367.         if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {
368.             m->in_channel_idx = av_get_channel_layout_channel_index(
                                     ^
369.                 inlink->channel_layout, m->in_channel);
370.         }

libavutil/channel_layout.c:198:1: <LHS trace>
196. }
197. 
198. int av_get_channel_layout_channel_index(uint64_t channel_layout,
     ^
199.                                         uint64_t channel)
200. {

libavutil/channel_layout.c:198:1: Parameter `channel`
  196. }
  197. 
  198. int av_get_channel_layout_channel_index(uint64_t channel_layout,
       ^
  199.                                         uint64_t channel)
  200. {

libavutil/channel_layout.c:204:5: Binary operation: ([0, 126] - 1):unsigned64 by call to `av_get_channel_layout_channel_index` 
  202.         av_get_channel_layout_nb_channels(channel) != 1)
  203.         return AVERROR(EINVAL);
  204.     channel_layout &= channel - 1;
           ^
  205.     return av_get_channel_layout_nb_channels(channel_layout);
  206. }

int av_get_channel_layout_channel_index(uint64_t channel_layout,
                                        uint64_t channel)
{
    if (!(channel_layout & channel) ||
        av_get_channel_layout_nb_channels(channel) != 1)
        return AVERROR(EINVAL);
    channel_layout &= channel - 1;
    return av_get_channel_layout_nb_channels(channel_layout);
}
['static int channelmap_config_input(AVFilterLink *inlink)\n{\n    AVFilterContext *ctx = inlink->dst;\n    ChannelMapContext *s = ctx->priv;\n    int nb_channels = av_get_channel_layout_nb_channels(inlink->channel_layout);\n    int i, err = 0;\n    const char *channel_name;\n    char layout_name[256];\n    for (i = 0; i < s->nch; i++) {\n        struct ChannelMap *m = &s->map[i];\n        if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {\n            m->in_channel_idx = av_get_channel_layout_channel_index(\n                inlink->channel_layout, m->in_channel);\n        }\n        if (m->in_channel_idx < 0 || m->in_channel_idx >= nb_channels) {\n            av_get_channel_layout_string(layout_name, sizeof(layout_name),\n                                         0, inlink->channel_layout);\n            if (m->in_channel) {\n                channel_name = av_get_channel_name(m->in_channel);\n                av_log(ctx, AV_LOG_ERROR,\n                       "input channel \'%s\' not available from input layout \'%s\'\\n",\n                       channel_name, layout_name);\n            } else {\n                av_log(ctx, AV_LOG_ERROR,\n                       "input channel #%d not available from input layout \'%s\'\\n",\n                       m->in_channel_idx, layout_name);\n            }\n            err = AVERROR(EINVAL);\n        }\n    }\n    return err;\n}', 'int av_get_channel_layout_channel_index(uint64_t channel_layout,\n                                        uint64_t channel)\n{\n    if (!(channel_layout & channel) ||\n        av_get_channel_layout_nb_channels(channel) != 1)\n        return AVERROR(EINVAL);\n    channel_layout &= channel - 1;\n    return av_get_channel_layout_nb_channels(channel_layout);\n}']