aacsbr: Make the previous value of bs_num_env local to read_sbr_data().

[ffmpeg] / libavcodec / mpeg4audio.c

diff --git a/libavcodec/mpeg4audio.c b/libavcodec/mpeg4audio.c
index cbee0bfde2544bf5b834f704636ca6c3f1a4008f..0666bbbc42d5ff815602a22e9373f65cec918d85 100644 (file)
--- a/libavcodec/mpeg4audio.c
+++ b/libavcodec/mpeg4audio.c
@@ -24,6 +24,34 @@
 #include "put_bits.h"
 #include "mpeg4audio.h"
 
+/**
+ * Parse MPEG-4 audio configuration for ALS object type.
+ * @param[in] gb       bit reader context
+ * @param[in] c        MPEG4AudioConfig structure to fill
+ * @return on success 0 is returned, otherwise a value < 0
+ */
+static int parse_config_ALS(GetBitContext *gb, MPEG4AudioConfig *c)
+{
+    if (get_bits_left(gb) < 112)
+        return -1;
+
+    if (get_bits_long(gb, 32) != MKBETAG('A','L','S','\0'))
+        return -1;
+
+    // override AudioSpecificConfig channel configuration and sample rate
+    // which are buggy in old ALS conformance files
+    c->sample_rate = get_bits_long(gb, 32);
+
+    // skip number of samples
+    skip_bits_long(gb, 32);
+
+    // read number of channels
+    c->chan_config = 0;
+    c->channels    = get_bits(gb, 16) + 1;
+
+    return 0;
+}
+
 const int ff_mpeg4audio_sample_rates[16] = {
     96000, 88200, 64000, 48000, 44100, 32000,
     24000, 22050, 16000, 12000, 11025, 8000, 7350
@@ -36,7 +64,7 @@ const uint8_t ff_mpeg4audio_channels[8] = {
 static inline int get_object_type(GetBitContext *gb)
 {
     int object_type = get_bits(gb, 5);
-    if (object_type == 31)
+    if (object_type == AOT_ESCAPE)
         object_type = 32 + get_bits(gb, 6);
     return object_type;
 }
@@ -57,8 +85,12 @@ int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int buf_si
     c->object_type = get_object_type(&gb);
     c->sample_rate = get_sample_rate(&gb, &c->sampling_index);
     c->chan_config = get_bits(&gb, 4);
+    if (c->chan_config < FF_ARRAY_ELEMS(ff_mpeg4audio_channels))
+        c->channels = ff_mpeg4audio_channels[c->chan_config];
     c->sbr = -1;
-    if (c->object_type == AOT_SBR) {
+    if (c->object_type == AOT_SBR || (c->object_type == AOT_PS &&
+        // check for W6132 Annex YYYY draft MP3onMP4
+        !(show_bits(&gb, 3) & 0x03 && !(show_bits(&gb, 9) & 0x3F)))) {
         c->ext_object_type = c->object_type;
         c->sbr = 1;
         c->ext_sample_rate = get_sample_rate(&gb, &c->ext_sampling_index);
@@ -66,13 +98,24 @@ int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int buf_si
         if (c->object_type == AOT_ER_BSAC)
             c->ext_chan_config = get_bits(&gb, 4);
     } else {
-        c->ext_object_type = 0;
+        c->ext_object_type = AOT_NULL;
         c->ext_sample_rate = 0;
     }
     specific_config_bitindex = get_bits_count(&gb);
 
+    if (c->object_type == AOT_ALS) {
+        skip_bits(&gb, 5);
+        if (show_bits_long(&gb, 24) != MKBETAG('\0','A','L','S'))
+            skip_bits_long(&gb, 24);
+
+        specific_config_bitindex = get_bits_count(&gb);
+
+        if (parse_config_ALS(&gb, c))
+            return -1;
+    }
+
     if (c->ext_object_type != AOT_SBR) {
-        int bits_left = buf_size*8 - specific_config_bitindex;
+        int bits_left = buf_size*8 - get_bits_count(&gb);
         for (; bits_left > 15; bits_left--) {
             if (show_bits(&gb, 11) == 0x2b7) { // sync extension
                 get_bits(&gb, 11);