From d8cec2d7fc1c2c5b6f82b8743b3cfd04cd4bb8cc Mon Sep 17 00:00:00 2001 From: Justin Ruggles Date: Sun, 20 Nov 2011 20:16:05 -0500 Subject: [PATCH] adx: move header decoding to ADX common code --- libavcodec/adx.c | 47 +++++++++++++++++++++++++++++++++++++++++++++ libavcodec/adx.h | 21 ++++++++++++++++++++ libavcodec/adxdec.c | 42 ++++++---------------------------------- 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 + +#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,