diff --git a/gst/audioparsers/gstflacparse.c b/gst/audioparsers/gstflacparse.c index ba9d7c4e67..0670fc05a4 100644 --- a/gst/audioparsers/gstflacparse.c +++ b/gst/audioparsers/gstflacparse.c @@ -114,6 +114,63 @@ gst_flac_calculate_crc8 (const guint8 * data, guint length) return crc; } +/* CRC-16, poly = x^16 + x^15 + x^2 + x^0, init = 0 */ +static const guint16 crc16_table[256] = { + 0x0000, 0x8005, 0x800f, 0x000a, 0x801b, 0x001e, 0x0014, 0x8011, + 0x8033, 0x0036, 0x003c, 0x8039, 0x0028, 0x802d, 0x8027, 0x0022, + 0x8063, 0x0066, 0x006c, 0x8069, 0x0078, 0x807d, 0x8077, 0x0072, + 0x0050, 0x8055, 0x805f, 0x005a, 0x804b, 0x004e, 0x0044, 0x8041, + 0x80c3, 0x00c6, 0x00cc, 0x80c9, 0x00d8, 0x80dd, 0x80d7, 0x00d2, + 0x00f0, 0x80f5, 0x80ff, 0x00fa, 0x80eb, 0x00ee, 0x00e4, 0x80e1, + 0x00a0, 0x80a5, 0x80af, 0x00aa, 0x80bb, 0x00be, 0x00b4, 0x80b1, + 0x8093, 0x0096, 0x009c, 0x8099, 0x0088, 0x808d, 0x8087, 0x0082, + 0x8183, 0x0186, 0x018c, 0x8189, 0x0198, 0x819d, 0x8197, 0x0192, + 0x01b0, 0x81b5, 0x81bf, 0x01ba, 0x81ab, 0x01ae, 0x01a4, 0x81a1, + 0x01e0, 0x81e5, 0x81ef, 0x01ea, 0x81fb, 0x01fe, 0x01f4, 0x81f1, + 0x81d3, 0x01d6, 0x01dc, 0x81d9, 0x01c8, 0x81cd, 0x81c7, 0x01c2, + 0x0140, 0x8145, 0x814f, 0x014a, 0x815b, 0x015e, 0x0154, 0x8151, + 0x8173, 0x0176, 0x017c, 0x8179, 0x0168, 0x816d, 0x8167, 0x0162, + 0x8123, 0x0126, 0x012c, 0x8129, 0x0138, 0x813d, 0x8137, 0x0132, + 0x0110, 0x8115, 0x811f, 0x011a, 0x810b, 0x010e, 0x0104, 0x8101, + 0x8303, 0x0306, 0x030c, 0x8309, 0x0318, 0x831d, 0x8317, 0x0312, + 0x0330, 0x8335, 0x833f, 0x033a, 0x832b, 0x032e, 0x0324, 0x8321, + 0x0360, 0x8365, 0x836f, 0x036a, 0x837b, 0x037e, 0x0374, 0x8371, + 0x8353, 0x0356, 0x035c, 0x8359, 0x0348, 0x834d, 0x8347, 0x0342, + 0x03c0, 0x83c5, 0x83cf, 0x03ca, 0x83db, 0x03de, 0x03d4, 0x83d1, + 0x83f3, 0x03f6, 0x03fc, 0x83f9, 0x03e8, 0x83ed, 0x83e7, 0x03e2, + 0x83a3, 0x03a6, 0x03ac, 0x83a9, 0x03b8, 0x83bd, 0x83b7, 0x03b2, + 0x0390, 0x8395, 0x839f, 0x039a, 0x838b, 0x038e, 0x0384, 0x8381, + 0x0280, 0x8285, 0x828f, 0x028a, 0x829b, 0x029e, 0x0294, 0x8291, + 0x82b3, 0x02b6, 0x02bc, 0x82b9, 0x02a8, 0x82ad, 0x82a7, 0x02a2, + 0x82e3, 0x02e6, 0x02ec, 0x82e9, 0x02f8, 0x82fd, 0x82f7, 0x02f2, + 0x02d0, 0x82d5, 0x82df, 0x02da, 0x82cb, 0x02ce, 0x02c4, 0x82c1, + 0x8243, 0x0246, 0x024c, 0x8249, 0x0258, 0x825d, 0x8257, 0x0252, + 0x0270, 0x8275, 0x827f, 0x027a, 0x826b, 0x026e, 0x0264, 0x8261, + 0x0220, 0x8225, 0x822f, 0x022a, 0x823b, 0x023e, 0x0234, 0x8231, + 0x8213, 0x0216, 0x021c, 0x8219, 0x0208, 0x820d, 0x8207, 0x0202 +}; + +static guint16 +gst_flac_calculate_crc16 (const guint8 * data, guint length) +{ + guint16 crc = 0; + + while (length--) { + crc = ((crc << 8) ^ crc16_table[(crc >> 8) ^ *data]) & 0xffff; + data++; + } + + return crc; +} + +enum +{ + PROP_0, + PROP_CHECK_FRAME_CHECKSUMS +}; + +#define DEFAULT_CHECK_FRAME_CHECKSUMS FALSE + static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, @@ -128,6 +185,10 @@ static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink", ); static void gst_flac_parse_finalize (GObject * object); +static void gst_flac_parse_set_property (GObject * object, guint prop_id, + const GValue * value, GParamSpec * pspec); +static void gst_flac_parse_get_property (GObject * object, guint prop_id, + GValue * value, GParamSpec * pspec); static gboolean gst_flac_parse_start (GstBaseParse * parse); static gboolean gst_flac_parse_stop (GstBaseParse * parse); @@ -167,6 +228,14 @@ gst_flac_parse_class_init (GstFlacParseClass * klass) GstBaseParseClass *baseparse_class = GST_BASE_PARSE_CLASS (klass); gobject_class->finalize = gst_flac_parse_finalize; + gobject_class->set_property = gst_flac_parse_set_property; + gobject_class->get_property = gst_flac_parse_get_property; + + g_object_class_install_property (gobject_class, PROP_CHECK_FRAME_CHECKSUMS, + g_param_spec_boolean ("check-frame-checksums", "Check Frame Checksums", + "Check the overall checksums of every frame", + DEFAULT_CHECK_FRAME_CHECKSUMS, + G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); baseparse_class->start = GST_DEBUG_FUNCPTR (gst_flac_parse_start); baseparse_class->stop = GST_DEBUG_FUNCPTR (gst_flac_parse_stop); @@ -180,6 +249,39 @@ gst_flac_parse_class_init (GstFlacParseClass * klass) static void gst_flac_parse_init (GstFlacParse * flacparse, GstFlacParseClass * klass) { + flacparse->check_frame_checksums = DEFAULT_CHECK_FRAME_CHECKSUMS; +} + +static void +gst_flac_parse_set_property (GObject * object, guint prop_id, + const GValue * value, GParamSpec * pspec) +{ + GstFlacParse *flacparse = GST_FLAC_PARSE (object); + + switch (prop_id) { + case PROP_CHECK_FRAME_CHECKSUMS: + flacparse->check_frame_checksums = g_value_get_boolean (value); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +gst_flac_parse_get_property (GObject * object, guint prop_id, + GValue * value, GParamSpec * pspec) +{ + GstFlacParse *flacparse = GST_FLAC_PARSE (object); + + switch (prop_id) { + case PROP_CHECK_FRAME_CHECKSUMS: + g_value_set_boolean (value, flacparse->check_frame_checksums); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } } static void @@ -659,9 +761,22 @@ gst_flac_parse_get_frame_size (GstFlacParse * flacparse, GstBuffer * buffer, /* zero padding to byte alignment */ gst_bit_reader_skip_to_byte (&reader); - /* Skip crc-16 for the complete frame */ - if (!gst_bit_reader_skip (&reader, 16)) - goto need_more_data; + if (flacparse->check_frame_checksums) { + guint16 actual_crc16, expected_crc16; + + if (!gst_bit_reader_get_bits_uint16 (&reader, &expected_crc16, 16)) + goto need_more_data; + + actual_crc16 = + gst_flac_calculate_crc16 (GST_BUFFER_DATA (buffer), + (gst_bit_reader_get_pos (&reader) / 8) - 2); + if (actual_crc16 != expected_crc16) + goto error; + } else { + /* Skip crc-16 for the complete frame */ + if (!gst_bit_reader_skip (&reader, 16)) + goto need_more_data; + } *framesize_ret = gst_bit_reader_get_pos (&reader) / 8; diff --git a/gst/audioparsers/gstflacparse.h b/gst/audioparsers/gstflacparse.h index af57ba7863..4730e235ce 100644 --- a/gst/audioparsers/gstflacparse.h +++ b/gst/audioparsers/gstflacparse.h @@ -54,6 +54,9 @@ typedef struct { struct _GstFlacParse { GstBaseParse parent; + /* Properties */ + gboolean check_frame_checksums; + GstFlacParseState state; gint64 upstream_length;