diff mbox

[FFmpeg-devel,06/10] avformat/dtsdec: switch to common frame header parsing function

Message ID 20170710141140.20075-6-foobaz86@gmail.com
State Accepted
Commit 3b7ec920af42f1dc3676b72db9e617227c220436
Headers show

Commit Message

foo86 July 10, 2017, 2:11 p.m. UTC
This makes probing for regular DTS more strict because more header
fields are checked and values not supported by decoder are now rejected.

Also fixes an issue original code had with 14-bit streams: 96 bits of
header were expected, however only 84 bits were converted, which was not
enough to parse LFE flag.
---
 libavformat/dtsdec.c | 39 +++++++++------------------------------
 1 file changed, 9 insertions(+), 30 deletions(-)
diff mbox

Patch

diff --git a/libavformat/dtsdec.c b/libavformat/dtsdec.c
index 8c985b8877..6e0048f9bc 100644
--- a/libavformat/dtsdec.c
+++ b/libavformat/dtsdec.c
@@ -35,13 +35,13 @@  static int dts_probe(AVProbeData *p)
     uint32_t state = -1;
     int markers[4*16] = {0};
     int exss_markers = 0, exss_nextpos = 0;
-    int sum, max, pos, i;
+    int sum, max, pos, ret, i;
     int64_t diff = 0;
-    uint8_t hdr[12 + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 };
+    uint8_t hdr[DCA_CORE_FRAME_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 };
 
     for (pos = FFMIN(4096, p->buf_size); pos < p->buf_size - 2; pos += 2) {
-        int marker, sample_blocks, sample_rate, sr_code, framesize;
-        int lfe, wide_hdr, hdr_size;
+        int marker, wide_hdr, hdr_size, framesize;
+        DCACoreFrameHeader h;
         GetBitContext gb;
 
         bufp = buf = p->buf + pos;
@@ -98,36 +98,15 @@  static int dts_probe(AVProbeData *p)
         else
             continue;
 
-        if (avpriv_dca_convert_bitstream(buf-2, 12, hdr, 12) < 0)
+        if ((ret = avpriv_dca_convert_bitstream(buf - 2, DCA_CORE_FRAME_HEADER_SIZE,
+                                                hdr,     DCA_CORE_FRAME_HEADER_SIZE)) < 0)
             continue;
-
-        init_get_bits(&gb, hdr, 96);
-        skip_bits_long(&gb, 39);
-
-        sample_blocks = get_bits(&gb, 7) + 1;
-        if (sample_blocks < 8)
+        if (init_get_bits8(&gb, hdr, ret) < 0)
             continue;
-
-        framesize = get_bits(&gb, 14) + 1;
-        if (framesize < 95)
-            continue;
-
-        skip_bits(&gb, 6);
-        sr_code = get_bits(&gb, 4);
-        sample_rate = avpriv_dca_sample_rates[sr_code];
-        if (sample_rate == 0)
-            continue;
-
-        get_bits(&gb, 5);
-        if (get_bits(&gb, 1))
-            continue;
-
-        skip_bits_long(&gb, 9);
-        lfe = get_bits(&gb, 2);
-        if (lfe > 2)
+        if (avpriv_dca_parse_core_frame_header(&gb, &h) < 0)
             continue;
 
-        marker += 4* sr_code;
+        marker += 4 * h.sr_code;
 
         markers[marker] ++;
     }