Change filtergraph init for FFmpeg 8 compatibility

[stronk-dev]

Minor change - splits up the avfilter_graph_create_filter command into a separate alloc & init. AFAIK this is the correct order of operations (with av_opt_set_int_list in between).

[j0sh]

Looks like av_opt_set_int_list is also deprecated; this threw an error last time I looked at ffmpeg8 compatibility.

I was able to get things to compile with the following (but haven't actually tested it)

diff --git a/ffmpeg/filter.c b/ffmpeg/filter.c
index bb0cf93f4a..deba5cd86d 100644
--- a/ffmpeg/filter.c
+++ b/ffmpeg/filter.c
@@ -57,6 +57,7 @@ int init_video_filters(struct input_ctx *ictx, struct output_ctx *octx, AVFrame
     AVFilterInOut *inputs  = NULL;
     AVRational time_base = ictx->ic->streams[ictx->vi]->time_base;
     enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUV420P, AV_PIX_FMT_CUDA, AV_PIX_FMT_NONE }; // XXX ensure the encoder allows this
+    int nb_pix_fmts = sizeof(pix_fmts) / sizeof(pix_fmts[0]);
     struct filter_ctx *vf = &octx->vf;
     char *filters_descr = octx->vfilters;
     enum AVPixelFormat in_pix_fmt = ictx->vc->pix_fmt;
@@ -104,8 +105,8 @@ int init_video_filters(struct input_ctx *ictx, struct output_ctx *octx, AVFrame
                                        "out", NULL, NULL, vf->graph);
     if (ret < 0) LPMS_ERR(vf_init_cleanup, "Cannot create video buffer sink");
 
-    ret = av_opt_set_int_list(vf->sink_ctx, "pix_fmts", pix_fmts,
-                              AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN);
+    ret = av_opt_set_array(vf->sink_ctx, "pixel_formats", AV_OPT_SEARCH_CHILDREN,
+                           0, nb_pix_fmts, AV_OPT_TYPE_PIXEL_FMT, pix_fmts);
     if (ret < 0) LPMS_ERR(vf_init_cleanup, "Cannot set output pixel format");
 
     ret = filtergraph_parser(vf, filters_descr, &inputs, &outputs);
@@ -211,6 +212,7 @@ int init_signature_filters(struct output_ctx *octx, AVFrame *inf)
     AVFilterInOut *inputs  = NULL;
     AVRational time_base = octx->oc->streams[0]->time_base;
     enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUV420P, AV_PIX_FMT_CUDA, AV_PIX_FMT_NONE }; // XXX ensure the encoder allows this
+    int nb_pix_fmts = sizeof(pix_fmts) / sizeof(pix_fmts[0]);
     struct filter_ctx *sf = &octx->sf;
     char *filters_descr = octx->sfilters;
     enum AVPixelFormat in_pix_fmt = octx->vc->pix_fmt;
@@ -260,8 +262,8 @@ int init_signature_filters(struct output_ctx *octx, AVFrame *inf)
                                        "out", NULL, NULL, sf->graph);
     if (ret < 0) LPMS_ERR(sf_init_cleanup, "Cannot create video buffer sink");
 
-    ret = av_opt_set_int_list(sf->sink_ctx, "pix_fmts", pix_fmts,
-                              AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN);
+    ret = av_opt_set_array(sf->sink_ctx, "pixel_formats", AV_OPT_SEARCH_CHILDREN,
+                           0, nb_pix_fmts, AV_OPT_TYPE_PIXEL_FMT, pix_fmts);
     if (ret < 0) LPMS_ERR(sf_init_cleanup, "Cannot set output pixel format");
 
     ret = filtergraph_parser(sf, filters_descr, &inputs, &outputs);

BTW, for the ffmpeg8 bump: we can probably remove the signature stuff from LPMS / go-livepeer since I don't believe we are using it anymore. I just haven't gotten around to the surgery that's required to cleanly remove all signature references in both codebases.