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authorJustin Ruggles <justin.ruggles@gmail.com>2011-11-20 20:16:05 -0500
committerJustin Ruggles <justin.ruggles@gmail.com>2011-11-26 16:25:07 -0500
commitd8cec2d7fc1c2c5b6f82b8743b3cfd04cd4bb8cc (patch)
tree8cd8b599a47c1f5abde152edc6cd21251711c99c /libavcodec
parent7ff55d9bdbdd9df004bb45055049499380d0ae68 (diff)
downloadffmpeg-d8cec2d7fc1c2c5b6f82b8743b3cfd04cd4bb8cc.tar.gz
adx: move header decoding to ADX common code
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/adx.c47
-rw-r--r--libavcodec/adx.h21
-rw-r--r--libavcodec/adxdec.c42
3 files changed, 74 insertions, 36 deletions
diff --git a/libavcodec/adx.c b/libavcodec/adx.c
index bc3e8825ca..9f03e930be 100644
--- a/libavcodec/adx.c
+++ b/libavcodec/adx.c
@@ -18,6 +18,7 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "libavutil/intreadwrite.h"
#include "libavutil/mathematics.h"
#include "adx.h"
@@ -32,3 +33,49 @@ void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff)
coeff[0] = lrintf(c * 2.0 * (1 << bits));
coeff[1] = lrintf(-(c * c) * (1 << bits));
}
+
+int ff_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf, int bufsize,
+ int *header_size, int *coeff)
+{
+ int offset, cutoff;
+
+ if (bufsize < 24)
+ return AVERROR_INVALIDDATA;
+
+ if (AV_RB16(buf) != 0x8000)
+ return AVERROR_INVALIDDATA;
+ offset = AV_RB16(buf + 2) + 4;
+
+ /* if copyright string is within the provided data, validate it */
+ if (bufsize >= offset && memcmp(buf + offset - 6, "(c)CRI", 6))
+ return AVERROR_INVALIDDATA;
+
+ /* check for encoding=3 block_size=18, sample_size=4 */
+ if (buf[4] != 3 || buf[5] != 18 || buf[6] != 4) {
+ av_log_ask_for_sample(avctx, "unsupported ADX format\n");
+ return AVERROR_PATCHWELCOME;
+ }
+
+ /* channels */
+ avctx->channels = buf[7];
+ if (avctx->channels > 2)
+ return AVERROR_INVALIDDATA;
+
+ /* sample rate */
+ avctx->sample_rate = AV_RB32(buf + 8);
+ if (avctx->sample_rate < 1 ||
+ avctx->sample_rate > INT_MAX / (avctx->channels * BLOCK_SIZE * 8))
+ return AVERROR_INVALIDDATA;
+
+ /* bit rate */
+ avctx->bit_rate = avctx->sample_rate * avctx->channels * BLOCK_SIZE * 8 / BLOCK_SAMPLES;
+
+ /* LPC coefficients */
+ if (coeff) {
+ cutoff = AV_RB16(buf + 16);
+ ff_adx_calculate_coeffs(cutoff, avctx->sample_rate, COEFF_BITS, coeff);
+ }
+
+ *header_size = offset;
+ return 0;
+}
diff --git a/libavcodec/adx.h b/libavcodec/adx.h
index cd8c45bf6d..f68a3cb793 100644
--- a/libavcodec/adx.h
+++ b/libavcodec/adx.h
@@ -31,6 +31,10 @@
#ifndef AVCODEC_ADX_H
#define AVCODEC_ADX_H
+#include <stdint.h>
+
+#include "avcodec.h"
+
typedef struct {
int s1,s2;
} ADXChannelState;
@@ -47,6 +51,9 @@ typedef struct {
#define COEFF_BITS 12
+#define BLOCK_SIZE 18
+#define BLOCK_SAMPLES 32
+
/**
* Calculate LPC coefficients based on cutoff frequency and sample rate.
*
@@ -57,4 +64,18 @@ typedef struct {
*/
void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff);
+/**
+ * Decode ADX stream header.
+ * Sets avctx->channels and avctx->sample_rate.
+ *
+ * @param avctx codec context
+ * @param buf header data
+ * @param bufsize data size, should be at least 24 bytes
+ * @param[out] header_size size of ADX header
+ * @param[out] coeff 2 LPC coefficients, can be NULL
+ * @return data offset or negative error code if header is invalid
+ */
+int ff_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf, int bufsize,
+ int *header_size, int *coeff);
+
#endif /* AVCODEC_ADX_H */
diff --git a/libavcodec/adxdec.c b/libavcodec/adxdec.c
index e9226b2bd9..0b0eac262c 100644
--- a/libavcodec/adxdec.c
+++ b/libavcodec/adxdec.c
@@ -33,9 +33,6 @@
* adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
*/
-#define BLOCK_SIZE 18
-#define BLOCK_SAMPLES 32
-
static av_cold int adx_decode_init(AVCodecContext *avctx)
{
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
@@ -72,45 +69,18 @@ static void adx_decode(ADXContext *c, int16_t *out, const uint8_t *in, int ch)
prev->s2 = s2;
}
-/**
- * Decode stream header.
- *
- * @param avctx codec context
- * @param buf packet data
- * @param bufsize packet size
- * @return data offset or negative error code if header is invalid
- */
static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
int bufsize)
{
ADXContext *c = avctx->priv_data;
- int offset, cutoff;
-
- if (AV_RB16(buf) != 0x8000)
- return AVERROR_INVALIDDATA;
- offset = AV_RB16(buf + 2) + 4;
- if (bufsize < offset || memcmp(buf + offset - 6, "(c)CRI", 6))
- return AVERROR_INVALIDDATA;
-
- /* check for encoding=3 block_size=18, sample_size=4 */
- if (buf[4] != 3 || buf[5] != 18 || buf[6] != 4) {
- av_log_ask_for_sample(avctx, "unsupported ADX format\n");
- return AVERROR_PATCHWELCOME;
- }
-
- c->channels = avctx->channels = buf[7];
- if (avctx->channels > 2)
- return AVERROR_INVALIDDATA;
- avctx->sample_rate = AV_RB32(buf + 8);
- if (avctx->sample_rate < 1 ||
- avctx->sample_rate > INT_MAX / (avctx->channels * BLOCK_SIZE * 8))
- return AVERROR_INVALIDDATA;
- avctx->bit_rate = avctx->sample_rate * avctx->channels * BLOCK_SIZE * 8 / BLOCK_SAMPLES;
+ int ret, header_size;
- cutoff = AV_RB16(buf + 16);
- ff_adx_calculate_coeffs(cutoff, avctx->sample_rate, COEFF_BITS, c->coeff);
+ if ((ret = ff_adx_decode_header(avctx, buf, bufsize, &header_size,
+ c->coeff)) < 0)
+ return ret;
- return offset;
+ c->channels = avctx->channels;
+ return header_size;
}
static int adx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,