libavdevice/decklink: configurablity to set max queue size

Signed-off-by: Ravindra Patagar <rpatagar@akamai.com>
Signed-off-by: Marton Balint <cus@passwd.hu>

doc/indevs.texi

@@ -289,6 +289,11 @@ Sets the audio packet timestamp source. Must be @samp{video}, @samp{audio},
 If set to @samp{true}, color bars are drawn in the event of a signal loss.
 Defaults to @samp{true}.
 
+@item queue_size
+Sets maximum input buffer size in bytes. If the buffering reaches this value,
+incoming frames will be dropped.
+Defaults to @samp{1073741824}.
+
 @end table
 
 @subsection Examples

libavdevice/decklink_common.h

@@ -1,6 +1,7 @@
 /*
  * Blackmagic DeckLink common code
  * Copyright (c) 2013-2014 Ramiro Polla, Luca Barbato, Deti Fliegl
+ * Copyright (c) 2017 Akamai Technologies, Inc.
  *
  * This file is part of FFmpeg.
  *
@@ -38,6 +39,7 @@ typedef struct AVPacketQueue {
     pthread_mutex_t mutex;
     pthread_cond_t cond;
     AVFormatContext *avctx;
+    int64_t max_q_size;
 } AVPacketQueue;
 
 struct decklink_ctx {

libavdevice/decklink_common_c.h

@@ -1,6 +1,7 @@
 /*
  * Blackmagic DeckLink common code
  * Copyright (c) 2013-2014 Ramiro Polla
+ * Copyright (c) 2017 Akamai Technologies, Inc.
  *
  * This file is part of FFmpeg.
  *
@@ -48,6 +49,7 @@ struct decklink_cctx {
     int video_input;
     int draw_bars;
     char *format_code;
+    int64_t queue_size;
 };
 
 #endif /* AVDEVICE_DECKLINK_COMMON_C_H */

libavdevice/decklink_dec.cpp

@@ -1,6 +1,7 @@
 /*
  * Blackmagic DeckLink input
  * Copyright (c) 2013-2014 Luca Barbato, Deti Fliegl
+ * Copyright (c) 2017 Akamai Technologies, Inc.
  *
  * This file is part of FFmpeg.
  *
@@ -187,10 +188,12 @@ static uint8_t* teletext_data_unit_from_vanc_data(uint8_t *src, uint8_t *tgt, in
 
 static void avpacket_queue_init(AVFormatContext *avctx, AVPacketQueue *q)
 {
+    struct decklink_cctx *ctx = (struct decklink_cctx *)avctx->priv_data;
     memset(q, 0, sizeof(AVPacketQueue));
     pthread_mutex_init(&q->mutex, NULL);
     pthread_cond_init(&q->cond, NULL);
     q->avctx = avctx;
+    q->max_q_size = ctx->queue_size;
 }
 
 static void avpacket_queue_flush(AVPacketQueue *q)
@@ -230,8 +233,8 @@ static int avpacket_queue_put(AVPacketQueue *q, AVPacket *pkt)
 {
     AVPacketList *pkt1;
 
-    // Drop Packet if queue size is > 1GB
-    if (avpacket_queue_size(q) >  1024 * 1024 * 1024 ) {
+    // Drop Packet if queue size is > maximum queue size
+    if (avpacket_queue_size(q) > q->max_q_size) {
         av_log(q->avctx, AV_LOG_WARNING,  "Decklink input buffer overrun!\n");
         return -1;
     }

libavdevice/decklink_dec_c.c

@@ -1,6 +1,7 @@
 /*
  * Blackmagic DeckLink input
  * Copyright (c) 2014 Deti Fliegl
+ * Copyright (c) 2017 Akamai Technologies, Inc.
  *
  * This file is part of FFmpeg.
  *
@@ -64,6 +65,7 @@ static const AVOption options[] = {
     { "reference",     NULL,                                          0,  AV_OPT_TYPE_CONST, { .i64 = PTS_SRC_REFERENCE}, 0, 0, DEC, "pts_source"},
     { "wallclock",     NULL,                                          0,  AV_OPT_TYPE_CONST, { .i64 = PTS_SRC_WALLCLOCK}, 0, 0, DEC, "pts_source"},
     { "draw_bars",     "draw bars on signal loss" , OFFSET(draw_bars),    AV_OPT_TYPE_BOOL,  { .i64 = 1}, 0, 1, DEC },
+    { "queue_size",    "input queue buffer size",   OFFSET(queue_size),   AV_OPT_TYPE_INT64, { .i64 = (1024 * 1024 * 1024)}, 0, INT64_MAX, DEC },
     { NULL },
 };
 

libavdevice/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVDEVICE_VERSION_MAJOR  57
 #define LIBAVDEVICE_VERSION_MINOR   7
-#define LIBAVDEVICE_VERSION_MICRO 100
+#define LIBAVDEVICE_VERSION_MICRO 101
 
 #define LIBAVDEVICE_VERSION_INT AV_VERSION_INT(LIBAVDEVICE_VERSION_MAJOR, \
                                                LIBAVDEVICE_VERSION_MINOR, \