mpegaudio: move all header parsing to mpegaudiodecheader.[ch]

Signed-off-by: Mans Rullgard <mans@mansr.com>

1 files changed, 39 insertions, 2 deletions

diff --git a/libavcodec/mpegaudiodecheader.h b/libavcodec/mpegaudiodecheader.h
index 41a491b986..2991595b02 100644
--- a/libavcodec/mpegaudiodecheader.h
+++ b/libavcodec/mpegaudiodecheader.h
@@ -27,13 +27,50 @@
 #ifndef AVCODEC_MPEGAUDIODECHEADER_H
 #define AVCODEC_MPEGAUDIODECHEADER_H
 
-#include "libavutil/common.h"
-#include "mpegaudio.h"
+#include "avcodec.h"
 
+#define MP3_MASK 0xFFFE0CCF
+
+#define MPA_DECODE_HEADER \
+    int frame_size; \
+    int error_protection; \
+    int layer; \
+    int sample_rate; \
+    int sample_rate_index; /* between 0 and 8 */ \
+    int bit_rate; \
+    int nb_channels; \
+    int mode; \
+    int mode_ext; \
+    int lsf;
+
+typedef struct MPADecodeHeader {
+  MPA_DECODE_HEADER
+} MPADecodeHeader;
 
 /* header decoding. MUST check the header before because no
    consistency check is done there. Return 1 if free format found and
    that the frame size must be computed externally */
 int ff_mpegaudio_decode_header(MPADecodeHeader *s, uint32_t header);
 
+/* useful helper to get mpeg audio stream infos. Return -1 if error in
+   header, otherwise the coded frame size in bytes */
+int ff_mpa_decode_header(AVCodecContext *avctx, uint32_t head, int *sample_rate, int *channels, int *frame_size, int *bitrate);
+
+/* fast header check for resync */
+static inline int ff_mpa_check_header(uint32_t header){
+    /* header */
+    if ((header & 0xffe00000) != 0xffe00000)
+        return -1;
+    /* layer check */
+    if ((header & (3<<17)) == 0)
+        return -1;
+    /* bit rate */
+    if ((header & (0xf<<12)) == 0xf<<12)
+        return -1;
+    /* frequency */
+    if ((header & (3<<10)) == 3<<10)
+        return -1;
+    return 0;
+}
+
 #endif /* AVCODEC_MPEGAUDIODECHEADER_H */