vd_lavc: respect vd-lavc-software-fallback opt

There's an option that's supposed to stop mpv from falling back to
software decoding if hardware decoding fails. Except that it doesn't
work and can fallback to software decoding anyway. Correct this by
checking if all possible hwdec failed after the loop in
select_and_set_hwdec and that we have this option. If so, flag a bool to
force eof. In decode_frame afterwards, we then simply immediately return
an EOF.

1 files changed, 10 insertions, 2 deletions

diff --git a/video/decode/vd_lavc.c b/video/decode/vd_lavc.c
index 77f64aa8c5..1cd8ba4438 100644
--- a/video/decode/vd_lavc.c
+++ b/video/decode/vd_lavc.c
@@ -183,6 +183,7 @@ typedef struct lavc_ctx {
     const char *decoder;
     bool hwdec_failed;
     bool hwdec_notified;
+    bool force_eof;
 
     bool intra_only;
     int framedrop_flags;
@@ -589,7 +590,14 @@ static void select_and_set_hwdec(struct mp_filter *vd)
             MP_VERBOSE(vd, "Using underlying hw-decoder '%s'\n",
                        ctx->hwdec.codec->name);
     } else {
-        MP_VERBOSE(vd, "Using software decoding.\n");
+        // If software fallback is disabled and we get here, all hwdec must
+        // have failed. Tell the ctx to always force an eof.
+        if (ctx->opts->software_fallback == INT_MAX) {
+            MP_WARN(ctx, "Software decoding fallback is disabled.\n");
+            ctx->force_eof = true;
+        } else {
+            MP_VERBOSE(vd, "Using software decoding.\n");
+        }
     }
 }
 
@@ -1167,7 +1175,7 @@ static int decode_frame(struct mp_filter *vd)
     vd_ffmpeg_ctx *ctx = vd->priv;
     AVCodecContext *avctx = ctx->avctx;
 
-    if (!avctx)
+    if (!avctx || ctx->force_eof)
         return AVERROR_EOF;
 
     prepare_decoding(vd);