[FFmpeg-cvslog] libavcodec/adts_header: add frame_length field and avpriv function to parse AAC ADTS header
Nachiket Tarate
git at videolan.org
Wed Oct 13 07:48:21 EEST 2021
ffmpeg | branch: master | Nachiket Tarate <nachiket.programmer at gmail.com> | Wed Sep 22 00:28:58 2021 +0530| [343c03c61cdf311f5eebb43731a3e5fd116200dc] | committer: Steven Liu
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 at gmail.com>
Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=343c03c61cdf311f5eebb43731a3e5fd116200dc
---
libavcodec/adts_header.c | 1 +
libavcodec/adts_header.h | 15 +++++++++++++++
libavcodec/adts_parser.c | 31 +++++++++++++++++++++++++++++++
3 files changed, 47 insertions(+)
diff --git a/libavcodec/adts_header.c b/libavcodec/adts_header.c
index 0889820f8a..e4454529c4 100644
--- a/libavcodec/adts_header.c
+++ b/libavcodec/adts_header.c
@@ -66,6 +66,7 @@ int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr)
hdr->sample_rate = avpriv_mpeg4audio_sample_rates[sr];
hdr->samples = (rdb + 1) * 1024;
hdr->bit_rate = size * 8 * hdr->sample_rate / hdr->samples;
+ hdr->frame_length = size;
return size;
}
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 */
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
+}
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