From: Devesh <[email protected]>
---
libavformat/gsmdec.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/libavformat/gsmdec.c b/libavformat/gsmdec.c
index d13327d..1942ac1 100644
--- a/libavformat/gsmdec.c
+++ b/libavformat/gsmdec.c
@@ -28,12 +28,25 @@
#define GSM_BLOCK_SIZE 33
#define GSM_BLOCK_SAMPLES 160
#define GSM_SAMPLE_RATE 8000
+#define GSM_MAGIC_NUM 0xD
typedef struct GSMDemuxerContext {
AVClass *class;
int sample_rate;
} GSMDemuxerContext;
+static int gsm_probe(AVProbeData *p)
+{
+ /* check file size. */
+ if (p->buf_size < GSM_BLOCK_SIZE)
+ return 0;
+
+ if (((*p->buf & 0xF0)>>4) == GSM_MAGIC_NUM)
+ return AVPROBE_SCORE_MAX ;
+ return 0;
+}
+
+
static int gsm_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret, size;
@@ -94,6 +107,7 @@ AVInputFormat ff_gsm_demuxer = {
.priv_data_size = sizeof(GSMDemuxerContext),
.read_header = gsm_read_header,
.read_packet = gsm_read_packet,
+ .read_probe = gsm_probe,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "gsm",
.raw_codec_id = AV_CODEC_ID_GSM,
--
1.9.1
From 86ff714a525b9678ac61a2088e90d2b4ab5997e9 Mon Sep 17 00:00:00 2001
From: Devesh Singh <[email protected]>
Date: Sat, 28 Jan 2017 00:28:01 +0530
Subject: [PATCH 2/2] BugID 555: Fix to detect gsm packet data type, made check
more robust
---
libavformat/gsmdec.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 58 insertions(+), 3 deletions(-)
diff --git a/libavformat/gsmdec.c b/libavformat/gsmdec.c
index 1942ac1..979318b 100644
--- a/libavformat/gsmdec.c
+++ b/libavformat/gsmdec.c
@@ -28,21 +28,76 @@
#define GSM_BLOCK_SIZE 33
#define GSM_BLOCK_SAMPLES 160
#define GSM_SAMPLE_RATE 8000
-#define GSM_MAGIC_NUM 0xD
+#define GSM_MAGIC_NIBBLE 0xD
+#define ODD 1
+#define EVEN 0
typedef struct GSMDemuxerContext {
AVClass *class;
int sample_rate;
} GSMDemuxerContext;
+#define IS_MAGIC_NUM_PRESENT(a, b) b ? (((a & 0xF0) >> 4) == GSM_MAGIC_NIBBLE)
: ((a & 0x0F) == GSM_MAGIC_NIBBLE)
+
+static int gsm_check_every_nibble(AVProbeData *p, int index_first_frame,
uint8_t nibble)
+{
+ int indx, success;
+
+ success = 0x1;
+
+ for (indx = index_first_frame ; indx < p->buf_size; indx +=
GSM_BLOCK_SIZE) {
+
+ if (IS_MAGIC_NUM_PRESENT(*(p->buf + indx), nibble)) {
+
+ success &= 0x1;
+
+ } else {
+
+ success &= 0x0;
+ break;
+
+ }
+ }
+
+ return success;
+}
+
static int gsm_probe(AVProbeData *p)
{
+ int index_first_frame;
+ int success;
+
/* check file size. */
if (p->buf_size < GSM_BLOCK_SIZE)
return 0;
- if (((*p->buf & 0xF0)>>4) == GSM_MAGIC_NUM)
- return AVPROBE_SCORE_MAX ;
+ index_first_frame = 0;
+ success = 1;
+
+ /* Check if nibble is equal to GSM_MAGIC_NIBBLE and all other nibble at
offset of multiples of GSM_BLOCK_SIZE
+ are equal to GSM_MAGIC_NIBBLE */
+
+ for(index_first_frame = 0; index_first_frame < GSM_BLOCK_SIZE;
index_first_frame++) {
+
+ if (IS_MAGIC_NUM_PRESENT(*(p->buf + index_first_frame),ODD)) {
+
+ success = gsm_check_every_nibble(p, index_first_frame, ODD);
+
+ } else if (IS_MAGIC_NUM_PRESENT(*(p->buf + index_first_frame), EVEN)) {
+
+ success = gsm_check_every_nibble(p, index_first_frame, EVEN);
+
+ } else {
+
+ success = 0x0;
+ }
+
+ if(success & 0x1) {
+
+ return AVPROBE_SCORE_MAX;
+ }
+ }
+
return 0;
}
--
1.9.1
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