libavcodec/adts_header: add frame_length field and avpriv function to parse AAC ADTS header

These will be used by HLS demuxer in case of sample decryption.

Signed-off-by: Nachiket Tarate <nachiket.programmer@gmail.com>
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/libavcodec/adts_parser.c b/libavcodec/adts_parser.c
index 5c9f8ff6f2..4a1a8fd5f4 100644
--- a/libavcodec/adts_parser.c
+++ b/libavcodec/adts_parser.c
@@ -42,3 +42,34 @@ int av_adts_header_parse(const uint8_t *buf, uint32_t *samples, uint8_t *frames)
     return AVERROR(ENOSYS);
 #endif
 }
+
+int avpriv_adts_header_parse(AACADTSHeaderInfo **phdr, const uint8_t *buf, size_t size)
+{
+#if CONFIG_ADTS_HEADER
+    int ret = 0;
+    GetBitContext gb;
+
+    if (!phdr || !buf || size < AV_AAC_ADTS_HEADER_SIZE)
+        return AVERROR_INVALIDDATA;
+
+    *phdr = av_mallocz(sizeof(AACADTSHeaderInfo));
+    if (!*phdr)
+        return AVERROR(ENOMEM);
+
+    ret = init_get_bits8(&gb, buf, AV_AAC_ADTS_HEADER_SIZE);
+    if (ret < 0) {
+        av_freep(phdr);
+        return ret;
+    }
+
+    ret = ff_adts_header_parse(&gb, *phdr);
+    if (ret < 0) {
+        av_freep(phdr);
+        return ret;
+    }
+
+    return 0;
+#else
+    return AVERROR(ENOSYS);
+#endif
+}