diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 156524a688..7551f7b548 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -1296,9 +1296,7 @@ typedef struct AVFormatContext {
 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
 
     /**
-     * Maximum size of the data read from input for determining
-     * the input container format.
-     * Demuxing only, set by the caller before avformat_open_input().
+     * @deprecated deprecated in favor of probesize2
      */
     unsigned int probesize;
 
@@ -1671,6 +1669,14 @@ typedef struct AVFormatContext {
      * Can be set to 0 to let avformat choose using a heuristic.
      */
     int64_t max_analyze_duration2;
+
+    /**
+     * Maximum size of the data read from input for determining
+     * the input container format.
+     * Demuxing only, set by the caller before avformat_open_input()
+     * via AVOptions (NO direct access).
+     */
+    int64_t probesize2;
 } AVFormatContext;
 
 int av_format_get_probe_score(const AVFormatContext *s);
diff --git a/libavformat/avio_internal.h b/libavformat/avio_internal.h
index bb2512707a..5864048811 100644
--- a/libavformat/avio_internal.h
+++ b/libavformat/avio_internal.h
@@ -95,7 +95,7 @@ int ffio_set_buf_size(AVIOContext *s, int buf_size);
  * within the current pos and pos+buf_size is possible.
  * Once the stream position moves outside this window this guarantee is lost.
  */
-int ffio_ensure_seekback(AVIOContext *s, int buf_size);
+int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size);
 
 int ffio_limit(AVIOContext *s, int size);
 
diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index 24c6b79097..c7e92032d2 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -767,7 +767,7 @@ int ffio_fdopen(AVIOContext **s, URLContext *h)
     return 0;
 }
 
-int ffio_ensure_seekback(AVIOContext *s, int buf_size)
+int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size)
 {
     uint8_t *buffer;
     int max_buffer_size = s->max_packet_size ?
diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index 04bc865c2a..405cade417 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -2242,12 +2242,13 @@ static void finished_reading_packet(AVFormatContext *s, int raw_packet_size)
         avio_skip(pb, skip);
 }
 
-static int handle_packets(MpegTSContext *ts, int nb_packets)
+static int handle_packets(MpegTSContext *ts, int64_t nb_packets)
 {
     AVFormatContext *s = ts->stream;
     uint8_t packet[TS_PACKET_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
     const uint8_t *data;
-    int packet_num, ret = 0;
+    int64_t packet_num;
+    int ret = 0;
 
     if (avio_tell(s->pb) != ts->last_pos) {
         int i;
@@ -2369,9 +2370,9 @@ static int mpegts_read_header(AVFormatContext *s)
     AVIOContext *pb   = s->pb;
     uint8_t buf[8 * 1024] = {0};
     int len;
-    int64_t pos;
+    int64_t pos, probesize = s->probesize ? s->probesize : s->probesize2;
 
-    ffio_ensure_seekback(pb, s->probesize);
+    ffio_ensure_seekback(pb, probesize);
 
     /* read the first 8192 bytes to get packet size */
     pos = avio_tell(pb);
@@ -2394,7 +2395,7 @@ static int mpegts_read_header(AVFormatContext *s)
 
         mpegts_open_section_filter(ts, PAT_PID, pat_cb, ts, 1);
 
-        handle_packets(ts, s->probesize / ts->raw_packet_size);
+        handle_packets(ts, probesize / ts->raw_packet_size);
         /* if could not find service, enable auto_guess */
 
         ts->auto_guess = 1;
diff --git a/libavformat/options_table.h b/libavformat/options_table.h
index e3943fd5f3..94cd65cb59 100644
--- a/libavformat/options_table.h
+++ b/libavformat/options_table.h
@@ -36,7 +36,7 @@
 static const AVOption avformat_options[] = {
 {"avioflags", NULL, OFFSET(avio_flags), AV_OPT_TYPE_FLAGS, {.i64 = DEFAULT }, INT_MIN, INT_MAX, D|E, "avioflags"},
 {"direct", "reduce buffering", 0, AV_OPT_TYPE_CONST, {.i64 = AVIO_FLAG_DIRECT }, INT_MIN, INT_MAX, D|E, "avioflags"},
-{"probesize", "set probing size", OFFSET(probesize), AV_OPT_TYPE_INT, {.i64 = 5000000 }, 32, INT_MAX, D},
+{"probesize", "set probing size", OFFSET(probesize2), AV_OPT_TYPE_INT64, {.i64 = 5000000 }, 32, INT64_MAX, D},
 {"formatprobesize", "number of bytes to probe file format", OFFSET(format_probesize), AV_OPT_TYPE_INT, {.i64 = PROBE_BUF_MAX}, 0, INT_MAX-1, D},
 {"packetsize", "set packet size", OFFSET(packet_size), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, 0, INT_MAX, E},
 {"fflags", NULL, OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = AVFMT_FLAG_FLUSH_PACKETS }, INT_MIN, INT_MAX, D|E, "fflags"},
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 4745060672..4cfebf23f9 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -2950,10 +2950,15 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
     int64_t old_offset  = avio_tell(ic->pb);
     // new streams might appear, no options for those
     int orig_nb_streams = ic->nb_streams;
-    int flush_codecs    = ic->probesize > 0;
+    int flush_codecs;
     int64_t max_analyze_duration = ic->max_analyze_duration2;
+    int64_t probesize = ic->probesize2;
+
     if (!max_analyze_duration)
         max_analyze_duration = ic->max_analyze_duration;
+    if (ic->probesize)
+        probesize = ic->probesize;
+    flush_codecs = probesize > 0;
 
     av_opt_set(ic, "skip_clear", "1", AV_OPT_SEARCH_CHILDREN);
 
@@ -3081,10 +3086,10 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
             }
         }
         /* We did not get all the codec info, but we read too much data. */
-        if (read_size >= ic->probesize) {
+        if (read_size >= probesize) {
             ret = count;
             av_log(ic, AV_LOG_DEBUG,
-                   "Probe buffer size limit of %d bytes reached\n", ic->probesize);
+                   "Probe buffer size limit of %"PRId64" bytes reached\n", probesize);
             for (i = 0; i < ic->nb_streams; i++)
                 if (!ic->streams[i]->r_frame_rate.num &&
                     ic->streams[i]->info->duration_count <= 1 &&
@@ -3328,7 +3333,7 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
         }
     }
 
-    if (ic->probesize)
+    if (probesize)
     estimate_timings(ic, old_offset);
 
     if (ret >= 0 && ic->nb_streams)
diff --git a/libavformat/version.h b/libavformat/version.h
index 573eb1ccc8..f58d2a719c 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFORMAT_VERSION_MAJOR 55
-#define LIBAVFORMAT_VERSION_MINOR 49
+#define LIBAVFORMAT_VERSION_MINOR 50
 #define LIBAVFORMAT_VERSION_MICRO 100
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \