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authorJames Almer <jamrial@gmail.com>2013-01-30 00:35:26 -0300
committerMichael Niedermayer <michaelni@gmx.at>2013-02-12 15:36:12 +0100
commit0957041221fa6d883c4ff245f2f3a452cca55b3f (patch)
tree33e265961ab9b60545792619fa2a4c550b1e91d4 /libavcodec/tta.c
parenta63dc846b502462c724c4791f830878301b0277a (diff)
downloadffmpeg-0957041221fa6d883c4ff245f2f3a452cca55b3f.tar.gz
lavc/tta: Add support for encrypted streams
Signed-off-by: James Almer <jamrial@gmail.com> Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/tta.c')
-rw-r--r--libavcodec/tta.c51
1 files changed, 47 insertions, 4 deletions
diff --git a/libavcodec/tta.c b/libavcodec/tta.c
index fb793be0bb..9b51a05fb4 100644
--- a/libavcodec/tta.c
+++ b/libavcodec/tta.c
@@ -34,6 +34,8 @@
#include "get_bits.h"
#include "internal.h"
#include "libavutil/crc.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/opt.h"
#define FORMAT_SIMPLE 1
#define FORMAT_ENCRYPTED 2
@@ -57,6 +59,7 @@ typedef struct TTAChannel {
} TTAChannel;
typedef struct TTAContext {
+ AVClass *class;
AVCodecContext *avctx;
AVFrame frame;
GetBitContext gb;
@@ -68,6 +71,8 @@ typedef struct TTAContext {
int32_t *decode_buffer;
+ uint8_t crc_pass[8];
+ uint8_t *pass;
TTAChannel *ch_ctx;
} TTAContext;
@@ -93,8 +98,13 @@ static const int32_t ttafilter_configs[4] = {
12
};
-static void ttafilter_init(TTAFilter *c, int32_t shift) {
+static void ttafilter_init(TTAContext *s, TTAFilter *c, int32_t shift) {
memset(c, 0, sizeof(TTAFilter));
+ if (s->pass) {
+ int i;
+ for (i = 0; i < 8; i++)
+ c->qm[i] = sign_extend(s->crc_pass[i], 8);
+ }
c->shift = shift;
c->round = shift_1[shift-1];
// c->round = 1 << (shift - 1);
@@ -173,6 +183,21 @@ static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
return 0;
}
+static uint64_t tta_check_crc64(uint8_t *pass)
+{
+ uint64_t crc = UINT64_MAX, poly = 0x42F0E1EBA9EA3693U;
+ uint8_t *end = pass + strlen(pass);
+ int i;
+
+ while (pass < end) {
+ crc ^= (uint64_t)*pass++ << 56;
+ for (i = 0; i < 8; i++)
+ crc = (crc << 1) ^ (poly & (((int64_t) crc) >> 63));
+ }
+
+ return crc ^ UINT64_MAX;
+}
+
static av_cold int tta_decode_init(AVCodecContext * avctx)
{
TTAContext *s = avctx->priv_data;
@@ -201,8 +226,11 @@ static av_cold int tta_decode_init(AVCodecContext * avctx)
return AVERROR_INVALIDDATA;
}
if (s->format == FORMAT_ENCRYPTED) {
- av_log_missing_feature(avctx, "Encrypted TTA", 0);
- return AVERROR_PATCHWELCOME;
+ if (!s->pass) {
+ av_log(avctx, AV_LOG_ERROR, "Missing password for encrypted stream. Please use the -password option\n");
+ return AVERROR(EINVAL);
+ }
+ AV_WL64(s->crc_pass, tta_check_crc64(s->pass));
}
avctx->channels = s->channels = get_bits(&s->gb, 16);
if (s->channels > 1 && s->channels < 9)
@@ -321,7 +349,7 @@ static int tta_decode_frame(AVCodecContext *avctx, void *data,
// init per channel states
for (i = 0; i < s->channels; i++) {
s->ch_ctx[i].predictor = 0;
- ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1]);
+ ttafilter_init(s, &s->ch_ctx[i].filter, ttafilter_configs[s->bps-1]);
rice_init(&s->ch_ctx[i].rice, 10, 10);
}
@@ -465,6 +493,20 @@ static av_cold int tta_decode_close(AVCodecContext *avctx) {
return 0;
}
+#define OFFSET(x) offsetof(TTAContext, x)
+#define DEC (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM)
+static const AVOption options[] = {
+ { "password", "Set decoding password", OFFSET(pass), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
+ { NULL },
+};
+
+static const AVClass tta_decoder_class = {
+ .class_name = "TTA Decoder",
+ .item_name = av_default_item_name,
+ .option = options,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
AVCodec ff_tta_decoder = {
.name = "tta",
.type = AVMEDIA_TYPE_AUDIO,
@@ -475,4 +517,5 @@ AVCodec ff_tta_decoder = {
.decode = tta_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
+ .priv_class = &tta_decoder_class,
};