[SCM] libav/experimental: Move decode_frame_header() from flacdec.c to flac.c/h to share with the forthcoming FLAC parser. Patch by Michael Chinen [mchinen at gmail]
siretart at users.alioth.debian.org
siretart at users.alioth.debian.org
Sun Jun 30 17:19:52 UTC 2013
The following commit has been merged in the experimental branch:
commit 625daac4bddda7858d16869c90ba7df95e7702c6
Author: Michael Chinen <mchinen at gmail.com>
Date: Tue Dec 7 13:30:18 2010 +0000
Move decode_frame_header() from flacdec.c to flac.c/h to share with the
forthcoming FLAC parser.
Patch by Michael Chinen [mchinen at gmail]
Originally committed as revision 25909 to svn://svn.ffmpeg.org/ffmpeg/trunk
diff --git a/libavcodec/flac.c b/libavcodec/flac.c
index a649e08..f6b65ce 100644
--- a/libavcodec/flac.c
+++ b/libavcodec/flac.c
@@ -19,7 +19,101 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "libavutil/crc.h"
#include "flac.h"
+#include "flacdata.h"
+
+static const int8_t sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 0 };
+
+static int64_t get_utf8(GetBitContext *gb)
+{
+ int64_t val;
+ GET_UTF8(val, get_bits(gb, 8), return -1;)
+ return val;
+}
+
+int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
+ FLACFrameInfo *fi)
+{
+ int bs_code, sr_code, bps_code;
+
+ /* frame sync code */
+ skip_bits(gb, 16);
+
+ /* block size and sample rate codes */
+ bs_code = get_bits(gb, 4);
+ sr_code = get_bits(gb, 4);
+
+ /* channels and decorrelation */
+ fi->ch_mode = get_bits(gb, 4);
+ if (fi->ch_mode < FLAC_MAX_CHANNELS) {
+ fi->channels = fi->ch_mode + 1;
+ fi->ch_mode = FLAC_CHMODE_INDEPENDENT;
+ } else if (fi->ch_mode <= FLAC_CHMODE_MID_SIDE) {
+ fi->channels = 2;
+ } else {
+ av_log(avctx, AV_LOG_ERROR, "invalid channel mode: %d\n", fi->ch_mode);
+ return -1;
+ }
+
+ /* bits per sample */
+ bps_code = get_bits(gb, 3);
+ if (bps_code == 3 || bps_code == 7) {
+ av_log(avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n",
+ bps_code);
+ return -1;
+ }
+ fi->bps = sample_size_table[bps_code];
+
+ /* reserved bit */
+ if (get_bits1(gb)) {
+ av_log(avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
+ return -1;
+ }
+
+ /* sample or frame count */
+ if (get_utf8(gb) < 0) {
+ av_log(avctx, AV_LOG_ERROR, "utf8 fscked\n");
+ return -1;
+ }
+
+ /* blocksize */
+ if (bs_code == 0) {
+ av_log(avctx, AV_LOG_ERROR, "reserved blocksize code: 0\n");
+ return -1;
+ } else if (bs_code == 6) {
+ fi->blocksize = get_bits(gb, 8) + 1;
+ } else if (bs_code == 7) {
+ fi->blocksize = get_bits(gb, 16) + 1;
+ } else {
+ fi->blocksize = ff_flac_blocksize_table[bs_code];
+ }
+
+ /* sample rate */
+ if (sr_code < 12) {
+ fi->samplerate = ff_flac_sample_rate_table[sr_code];
+ } else if (sr_code == 12) {
+ fi->samplerate = get_bits(gb, 8) * 1000;
+ } else if (sr_code == 13) {
+ fi->samplerate = get_bits(gb, 16);
+ } else if (sr_code == 14) {
+ fi->samplerate = get_bits(gb, 16) * 10;
+ } else {
+ av_log(avctx, AV_LOG_ERROR, "illegal sample rate code %d\n",
+ sr_code);
+ return -1;
+ }
+
+ /* header CRC-8 check */
+ skip_bits(gb, 8);
+ if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer,
+ get_bits_count(gb)/8)) {
+ av_log(avctx, AV_LOG_ERROR, "header crc mismatch\n");
+ return -1;
+ }
+
+ return 0;
+}
int ff_flac_get_max_frame_size(int blocksize, int ch, int bps)
{
diff --git a/libavcodec/flac.h b/libavcodec/flac.h
index 1b11463..fe38463 100644
--- a/libavcodec/flac.h
+++ b/libavcodec/flac.h
@@ -28,6 +28,7 @@
#define AVCODEC_FLAC_H
#include "avcodec.h"
+#include "get_bits.h"
#define FLAC_STREAMINFO_SIZE 34
#define FLAC_MAX_CHANNELS 8
@@ -120,4 +121,13 @@ void ff_flac_parse_block_header(const uint8_t *block_header,
*/
int ff_flac_get_max_frame_size(int blocksize, int ch, int bps);
+/**
+ * Validate and decode a frame header.
+ * @param avctx AVCodecContext to use as av_log() context
+ * @param gb GetBitContext from which to read frame header
+ * @param[out] fi frame information
+ * @return non-zero on error, 0 if ok
+ */
+int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
+ FLACFrameInfo *fi);
#endif /* AVCODEC_FLAC_H */
diff --git a/libavcodec/flacdec.c b/libavcodec/flacdec.c
index 8488a9d..f620694 100644
--- a/libavcodec/flacdec.c
+++ b/libavcodec/flacdec.c
@@ -67,16 +67,6 @@ typedef struct FLACContext {
unsigned int allocated_bitstream_size;
} FLACContext;
-static const int sample_size_table[] =
-{ 0, 8, 12, 0, 16, 20, 24, 0 };
-
-static int64_t get_utf8(GetBitContext *gb)
-{
- int64_t val;
- GET_UTF8(val, get_bits(gb, 8), return -1;)
- return val;
-}
-
static void allocate_buffers(FLACContext *s);
int ff_flac_is_extradata_valid(AVCodecContext *avctx,
@@ -480,103 +470,13 @@ static inline int decode_subframe(FLACContext *s, int channel)
return 0;
}
-/**
- * Validate and decode a frame header.
- * @param avctx AVCodecContext to use as av_log() context
- * @param gb GetBitContext from which to read frame header
- * @param[out] fi frame information
- * @return non-zero on error, 0 if ok
- */
-static int decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
- FLACFrameInfo *fi)
-{
- int bs_code, sr_code, bps_code;
-
- /* frame sync code */
- skip_bits(gb, 16);
-
- /* block size and sample rate codes */
- bs_code = get_bits(gb, 4);
- sr_code = get_bits(gb, 4);
-
- /* channels and decorrelation */
- fi->ch_mode = get_bits(gb, 4);
- if (fi->ch_mode < FLAC_MAX_CHANNELS) {
- fi->channels = fi->ch_mode + 1;
- fi->ch_mode = FLAC_CHMODE_INDEPENDENT;
- } else if (fi->ch_mode <= FLAC_CHMODE_MID_SIDE) {
- fi->channels = 2;
- } else {
- av_log(avctx, AV_LOG_ERROR, "invalid channel mode: %d\n", fi->ch_mode);
- return -1;
- }
-
- /* bits per sample */
- bps_code = get_bits(gb, 3);
- if (bps_code == 3 || bps_code == 7) {
- av_log(avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n",
- bps_code);
- return -1;
- }
- fi->bps = sample_size_table[bps_code];
-
- /* reserved bit */
- if (get_bits1(gb)) {
- av_log(avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
- return -1;
- }
-
- /* sample or frame count */
- if (get_utf8(gb) < 0) {
- av_log(avctx, AV_LOG_ERROR, "utf8 fscked\n");
- return -1;
- }
-
- /* blocksize */
- if (bs_code == 0) {
- av_log(avctx, AV_LOG_ERROR, "reserved blocksize code: 0\n");
- return -1;
- } else if (bs_code == 6) {
- fi->blocksize = get_bits(gb, 8) + 1;
- } else if (bs_code == 7) {
- fi->blocksize = get_bits(gb, 16) + 1;
- } else {
- fi->blocksize = ff_flac_blocksize_table[bs_code];
- }
-
- /* sample rate */
- if (sr_code < 12) {
- fi->samplerate = ff_flac_sample_rate_table[sr_code];
- } else if (sr_code == 12) {
- fi->samplerate = get_bits(gb, 8) * 1000;
- } else if (sr_code == 13) {
- fi->samplerate = get_bits(gb, 16);
- } else if (sr_code == 14) {
- fi->samplerate = get_bits(gb, 16) * 10;
- } else {
- av_log(avctx, AV_LOG_ERROR, "illegal sample rate code %d\n",
- sr_code);
- return -1;
- }
-
- /* header CRC-8 check */
- skip_bits(gb, 8);
- if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer,
- get_bits_count(gb)/8)) {
- av_log(avctx, AV_LOG_ERROR, "header crc mismatch\n");
- return -1;
- }
-
- return 0;
-}
-
static int decode_frame(FLACContext *s)
{
int i;
GetBitContext *gb = &s->gb;
FLACFrameInfo fi;
- if (decode_frame_header(s->avctx, gb, &fi)) {
+ if (ff_flac_decode_frame_header(s->avctx, gb, &fi)) {
av_log(s->avctx, AV_LOG_ERROR, "invalid frame header\n");
return -1;
}
--
Libav/FFmpeg packaging
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