您可能能够在我们的输出上下文中使用 Filter,尽管我没有尝试过。这里看起来是一个使用 Filterhttps://blog.birost.com/a?ID=01500-3825be8d-e578-4030-9e2e-a4f7160d1410的基本实现的人的例子。具体来说,下面的代码 (我意识到它与视频有关,但你应该能够修改为音频,并且可能能够摆脱很多这样的代码)。

static int init_filters(const char *filters_descr)
{
    char args[512];
    int ret;
    Filter *buffersrc  = avfilter_get_by_name("buffer");
    Filter *buffersink = avfilter_get_by_name("ffbuffersink");
    FilterInOut *outputs = avfilter_inout_alloc();
    FilterInOut *inputs  = avfilter_inout_alloc();
    enum PixelFormat pix_fmts[] = { _PIX_FMT_YUV420P, _PIX_FMT_NONE };
    BufferSinkParams *buffersink_params;
    filter_graph = avfilter_graph_alloc();
   /* buffer video source: the decoded frames from the decoder will be inserted here. */
    snprintf(args, sizeof(args),
            "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
            pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt,
            pCodecCtx->time_base.num, pCodecCtx->time_base.den,
            pCodecCtx->sample_aspect_ratio.num, pCodecCtx->sample_aspect_ratio.den);
    ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
                                       args, NULL, filter_graph);
    if (ret < 0) {
        printf("Cannot create buffer source\n");
        return ret;
    }
   /* buffer video sink: to terminate the filter chain. */
    buffersink_params = av_buffersink_params_alloc();
    buffersink_params->pixel_fmts = pix_fmts;
    ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
                                       NULL, buffersink_params, filter_graph);
    av_free(buffersink_params);
    if (ret < 0) {
        printf("Cannot create buffer sink\n");
        return ret;
    }
   /* Endpoints for the filter graph. */
    outputs->name       = av_strdup("in");
    outputs->filter_ctx = buffersrc_ctx;
    outputs->pad_idx    = 0;
    outputs->next       = NULL;
    inputs->name       = av_strdup("out");
    inputs->filter_ctx = buffersink_ctx;
    inputs->pad_idx    = 0;
    inputs->next       = NULL;

Filter 已注册以下筛选器:

REGISTER_FILTER(ANULLSRC, anullsrc, asrc);
REGISTER_FILTER(ANULLSINK, anullsink, asink);

您可能能够以与示例代码使用相同的方式使用。我会认为一个空的 Packet 可以工作。它可能这种方法不起作用 (没有直接处理这个),但是如果你还没有,你可以尝试一下。如果你这样做,我很乐意听到结果。