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authorJustin Ruggles <justin.ruggles@gmail.com>2012-02-27 13:58:01 -0500
committerJustin Ruggles <justin.ruggles@gmail.com>2012-03-05 13:08:17 -0500
commit11ac796f7ab2738eff19ea18847355363c8cc797 (patch)
tree350b9316d20d7b04cbb6a43e2acfd92bc36e4fc2 /libavcodec/dca_parser.c
parent85469f1c9eb1e678f9d7135dd6bcc1df68072e29 (diff)
downloadffmpeg-11ac796f7ab2738eff19ea18847355363c8cc797.tar.gz
dca_parser: parse the sample rate and frame durations
Diffstat (limited to 'libavcodec/dca_parser.c')
-rw-r--r--libavcodec/dca_parser.c80
1 files changed, 79 insertions, 1 deletions
diff --git a/libavcodec/dca_parser.c b/libavcodec/dca_parser.c
index 136cc458ef..e7b2ce42cc 100644
--- a/libavcodec/dca_parser.c
+++ b/libavcodec/dca_parser.c
@@ -24,6 +24,10 @@
#include "parser.h"
#include "dca.h"
+#include "dcadata.h"
+#include "dca_parser.h"
+#include "get_bits.h"
+#include "put_bits.h"
typedef struct DCAParseContext {
ParseContext pc;
@@ -100,6 +104,71 @@ static av_cold int dca_parse_init(AVCodecParserContext * s)
return 0;
}
+int ff_dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst,
+ int max_size)
+{
+ uint32_t mrk;
+ int i, tmp;
+ const uint16_t *ssrc = (const uint16_t *) src;
+ uint16_t *sdst = (uint16_t *) dst;
+ PutBitContext pb;
+
+ if ((unsigned) src_size > (unsigned) max_size)
+ src_size = max_size;
+
+ mrk = AV_RB32(src);
+ switch (mrk) {
+ case DCA_MARKER_RAW_BE:
+ memcpy(dst, src, src_size);
+ return src_size;
+ case DCA_MARKER_RAW_LE:
+ for (i = 0; i < (src_size + 1) >> 1; i++)
+ *sdst++ = av_bswap16(*ssrc++);
+ return src_size;
+ case DCA_MARKER_14B_BE:
+ case DCA_MARKER_14B_LE:
+ init_put_bits(&pb, dst, max_size);
+ for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) {
+ tmp = ((mrk == DCA_MARKER_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF;
+ put_bits(&pb, 14, tmp);
+ }
+ flush_put_bits(&pb);
+ return (put_bits_count(&pb) + 7) >> 3;
+ default:
+ return AVERROR_INVALIDDATA;
+ }
+}
+
+static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
+ int *sample_rate)
+{
+ GetBitContext gb;
+ uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };
+ int ret, sample_blocks, sr_code;
+
+ if (buf_size < 12)
+ return AVERROR_INVALIDDATA;
+
+ if ((ret = ff_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
+ return ret;
+
+ init_get_bits(&gb, hdr, 96);
+
+ skip_bits_long(&gb, 39);
+ sample_blocks = get_bits(&gb, 7) + 1;
+ if (sample_blocks < 8)
+ return AVERROR_INVALIDDATA;
+ *duration = 256 * (sample_blocks / 8);
+
+ skip_bits(&gb, 20);
+ sr_code = get_bits(&gb, 4);
+ *sample_rate = dca_sample_rates[sr_code];
+ if (*sample_rate == 0)
+ return AVERROR_INVALIDDATA;
+
+ return 0;
+}
+
static int dca_parse(AVCodecParserContext * s,
AVCodecContext * avctx,
const uint8_t ** poutbuf, int *poutbuf_size,
@@ -107,7 +176,7 @@ static int dca_parse(AVCodecParserContext * s,
{
DCAParseContext *pc1 = s->priv_data;
ParseContext *pc = &pc1->pc;
- int next;
+ int next, duration, sample_rate;
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
@@ -120,6 +189,15 @@ static int dca_parse(AVCodecParserContext * s,
return buf_size;
}
}
+
+ /* read the duration and sample rate from the frame header */
+ if (!dca_parse_params(buf, buf_size, &duration, &sample_rate)) {
+ s->duration = duration;
+ if (!avctx->sample_rate)
+ avctx->sample_rate = sample_rate;
+ } else
+ s->duration = 0;
+
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;