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, 15 insertions, 0 deletions

diff --git a/libavcodec/adts_header.h b/libavcodec/adts_header.h
index f615f6a9f9..354d07e1f8 100644
--- a/libavcodec/adts_header.h
+++ b/libavcodec/adts_header.h
@@ -34,6 +34,7 @@ typedef struct AACADTSHeaderInfo {
     uint8_t  sampling_index;
     uint8_t  chan_config;
     uint8_t  num_aac_frames;
+    uint32_t frame_length;
 } AACADTSHeaderInfo;
 
 /**
@@ -47,4 +48,18 @@ typedef struct AACADTSHeaderInfo {
  */
 int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr);
 
+/**
+ * Parse the ADTS frame header contained in the buffer, which is
+ * the first 54 bits.
+ * @param[in]  buf  Pointer to buffer containing the first 54 bits of the frame.
+ * @param[in]  size Size of buffer containing the first 54 bits of the frame.
+ * @param[out] phdr Pointer to pointer to struct AACADTSHeaderInfo for which
+ * memory is allocated and header info is written into it. After using the header
+ * information, the allocated memory must be freed by using av_free.
+ * @return Returns 0 on success, -1 if there is a sync word mismatch,
+ * -2 if the version element is invalid, -3 if the sample rate
+ * element is invalid, or -4 if the bit rate element is invalid.
+ */
+int avpriv_adts_header_parse(AACADTSHeaderInfo **phdr, const uint8_t *buf, size_t size);
+
 #endif /* AVCODEC_ADTS_HEADER_H */