demux: add options to control maximum queue size

Add --demuxer-max-packets and --demuxer-max-bytes, which control the
maximum size of the packet queue. These can be helpful to avoid
excessive memory usage.

Memory usage is the reason why there's a limit in the first place. If a
file is more or less broken, and audio and video don't line up, the
decoders will fill up the packet queue trying to read more audio or
video, and the maximum sizes are required to avoid unbounded memory
allocation. Being able to override the maximum sizes is useful; either
for restricting memory usage further, or enlarging the sizes when
attempting to play various broken files.

2 files changed, 6 insertions, 0 deletions

diff --git a/options/options.c b/options/options.c
index 93f7b4a45e..1528f06ee5 100644
--- a/options/options.c
+++ b/options/options.c
@@ -242,6 +242,8 @@ const m_option_t mp_opts[] = {
     OPT_STRING("sub-demuxer", sub_demuxer_name, 0),
     OPT_FLAG("demuxer-thread", demuxer_thread, 0),
     OPT_DOUBLE("demuxer-readahead-secs", demuxer_min_secs, M_OPT_MIN, .min = 0),
+    OPT_INTRANGE("demuxer-max-packets", demuxer_max_packs, 0, 0, INT_MAX),
+    OPT_INTRANGE("demuxer-max-bytes", demuxer_max_bytes, 0, 0, INT_MAX),
 
     OPT_FLAG("force-seekable", force_seekable, 0),
 
@@ -718,6 +720,8 @@ const struct MPOpts mp_default_opts = {
         .back_buffer = 75000,
         .file_max = 1024 * 1024,
     },
+    .demuxer_max_packs = 16000,
+    .demuxer_max_bytes = 400 * 1024 * 1024,
     .demuxer_thread = 1,
     .demuxer_min_secs = 1.0,
     .network_rtsp_transport = 2,
diff --git a/options/options.h b/options/options.h
index 677b23f92e..4382831883 100644
--- a/options/options.h
+++ b/options/options.h
@@ -195,6 +195,8 @@ typedef struct MPOpts {
 
     char **audio_files;
     char *demuxer_name;
+    int demuxer_max_packs;
+    int demuxer_max_bytes;
     int demuxer_thread;
     double demuxer_min_secs;
     char *audio_demuxer_name;