[FFmpeg-devel] rmdec.c: add SIPR codec try #2
Ronald S. Bultje
rsbultje
Tue Mar 17 19:29:03 CET 2009
Hi Kostya & all,
On Tue, Mar 17, 2009 at 10:28 AM, Kostya <kostya.shishkov at gmail.com> wrote:
> On Tue, Mar 17, 2009 at 09:29:39AM -0400, Ronald S. Bultje wrote:
>> + ? ? ? ? ? ?ast->audio_framesize = st->codec->block_align;
>> + ? ? ? ? ? ?if (st->codec->codec_id == CODEC_ID_SIPR) {
>> + ? ? ? ? ? ? ? ?st->codec->block_align = sipr_subpk_size[flavor];
>
> bounds check needed (flavor is read as 16 bits and you have only 4
> subpacket sizes)
Changed.
>> + ? ? ? ? ? ? ? ?/* perform reordering */
>> + ? ? ? ? ? ? ? ?int n;
>> + ? ? ? ? ? ? ? ?int bs = h * w * 2 / 96; ?// nibbles per subpacket
>> +
>> + ? ? ? ? ? ? ? ?for (n = 0; n < 38; n++) {
>> + ? ? ? ? ? ? ? ? ? ?int j;
>> + ? ? ? ? ? ? ? ? ? ?int i = bs * sipr_swaps[n][0];
>> + ? ? ? ? ? ? ? ? ? ?int o = bs * sipr_swaps[n][1];
>> + ? ? ? ? ? ? ? ? ? ?uint8_t *buf = ast->pkt.data;
>> +
>> + ? ? ? ? ? ? ? ? ? ?/* swap 4bit-nibbles of block 'i' with 'o' */
>> + ? ? ? ? ? ? ? ? ? ?for (j = 0; j < bs; j++, i++, o++) {
>> + ? ? ? ? ? ? ? ? ? ? ? ?int x = (buf[i >> 1] >> (4 * (i & 1))) & 0xF,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ?y = (buf[o >> 1] >> (4 * (o & 1))) & 0xF;
> [style nit suppressed]
>> +
>> + ? ? ? ? ? ? ? ? ? ? ? ?buf[o >> 1] = (x << (4 * (o & 1))) |
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ?(buf[o >> 1] & (0xF << (4 * !(o & 1))));
>> + ? ? ? ? ? ? ? ? ? ? ? ?buf[i >> 1] = (y << (4 * (i & 1))) |
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ?(buf[i >> 1] & (0xF << (4 * !(i & 1))));
>
> this is not very readable and the value is swapped twice.
> I think full swapping should be done at each iteration, probably
> with splitting for (i&1 == o&1) and (i&1 != o&1) cases
Gotcha, I think the attached should be faster. Not the prettiest
stylistically... Anyway, resulting frames are still identical to
original code.
>> + ? ? ? ? ? ? ? ? ? ?}
>> + ? ? ? ? ? ? ? ?}
>> + ? ? ? ? ? ?}
>> +
>
> better move it to separate function like AC3 byte swapping
> (or merge them into common codec_data_swap()
Done, see attached.
Ronald
-------------- next part --------------
Index: ffmpeg-svn/libavformat/rmdec.c
===================================================================
--- ffmpeg-svn.orig/libavformat/rmdec.c 2009-03-17 08:59:25.000000000 -0400
+++ ffmpeg-svn/libavformat/rmdec.c 2009-03-17 14:26:46.000000000 -0400
@@ -48,6 +48,21 @@
int audio_pkt_cnt; ///< Output packet counter
} RMDemuxContext;
+static const unsigned char sipr_swaps[38][2] = {
+ { 0, 63 }, { 1, 22 }, { 2, 44 }, { 3, 90 },
+ { 5, 81 }, { 7, 31 }, { 8, 86 }, { 9, 58 },
+ { 10, 36 }, { 12, 68 }, { 13, 39 }, { 14, 73 },
+ { 15, 53 }, { 16, 69 }, { 17, 57 }, { 19, 88 },
+ { 20, 34 }, { 21, 71 }, { 24, 46 }, { 25, 94 },
+ { 26, 54 }, { 28, 75 }, { 29, 50 }, { 32, 70 },
+ { 33, 92 }, { 35, 74 }, { 38, 85 }, { 40, 56 },
+ { 42, 87 }, { 43, 65 }, { 45, 59 }, { 48, 79 },
+ { 49, 93 }, { 51, 89 }, { 55, 95 }, { 61, 76 },
+ { 67, 83 }, { 77, 80 }
+};
+
+static const unsigned char sipr_subpk_size[4] = { 29, 19, 37, 20 };
+
static inline void get_strl(ByteIOContext *pb, char *buf, int buf_size, int len)
{
int i;
@@ -171,19 +186,28 @@
return -1;
}
- if(sub_packet_size <= 0){
- av_log(s, AV_LOG_ERROR, "sub_packet_size is invalid\n");
- return -1;
- }
-
if (!strcmp(buf, "cook")) st->codec->codec_id = CODEC_ID_COOK;
else if (!strcmp(buf, "sipr")) st->codec->codec_id = CODEC_ID_SIPR;
else st->codec->codec_id = CODEC_ID_ATRAC3;
+
+ ast->audio_framesize = st->codec->block_align;
+ if (st->codec->codec_id == CODEC_ID_SIPR) {
+ if (flavor > 3) {
+ av_log(s, AV_LOG_ERROR, "bad SIPR file flavor %d\n",
+ flavor);
+ return -1;
+ }
+ st->codec->block_align = sipr_subpk_size[flavor];
+ } else {
+ if(sub_packet_size <= 0){
+ av_log(s, AV_LOG_ERROR, "sub_packet_size is invalid\n");
+ return -1;
+ }
+ st->codec->block_align = ast->sub_packet_size;
+ }
st->codec->extradata_size= codecdata_length;
st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
- ast->audio_framesize = st->codec->block_align;
- st->codec->block_align = ast->sub_packet_size;
if(ast->audio_framesize >= UINT_MAX / sub_packet_h){
av_log(s, AV_LOG_ERROR, "rm->audio_framesize * sub_packet_h too large\n");
@@ -637,6 +661,39 @@
}
}
+/** perform 4-bit block reordering for SIPR data */
+static void
+rm_reorder_sipr_data (RMStream *ast)
+{
+ int n, bs = ast->sub_packet_h * ast->audio_framesize * 2 / 96; // nibbles per subpacket
+
+ for (n = 0; n < 38; n++) {
+ int j;
+ int i = bs * sipr_swaps[n][0];
+ int o = bs * sipr_swaps[n][1];
+ uint8_t *buf = ast->pkt.data;
+
+#define LOOP_ITER \
+ for (j = 0; j < bs; j++, i++, o++) { \
+ int mask1 = (i & 1) ? 0xF0 : 0x0F, \
+ mask2 = (i & 1) ? 0x0F : 0xF0, \
+ tmp = buf[i >> 1] & mask1;
+#define LOOP_END }
+
+ /* swap 4bit-nibbles of block 'i' with 'o' */
+ if (!((i ^ o) & 1)) LOOP_ITER {
+ buf[i >> 1] = (buf[i >> 1] & mask2) | (buf[o >> 1] & mask1);
+ buf[o >> 1] = (buf[o >> 1] & mask2) | tmp;
+ } LOOP_END else if (i & 1) LOOP_ITER {
+ buf[i >> 1] = (buf[i >> 1] & mask2) | ((buf[o >> 1] & mask2) << 4);
+ buf[o >> 1] = (buf[o >> 1] & mask1) | (tmp >> 4);
+ } LOOP_END else /* o & 1 */ LOOP_ITER {
+ buf[i >> 1] = (buf[i >> 1] & mask2) | ((buf[o >> 1] & mask2) >> 4);
+ buf[o >> 1] = (buf[o >> 1] & mask1) | (tmp << 4);
+ } LOOP_END;
+ }
+}
+
int
ff_rm_parse_packet (AVFormatContext *s, ByteIOContext *pb,
AVStream *st, RMStream *ast, int len, AVPacket *pkt,
@@ -675,10 +732,16 @@
for (x = 0; x < w/sps; x++)
get_buffer(pb, ast->pkt.data+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), sps);
break;
+ case CODEC_ID_SIPR:
+ get_buffer(pb, ast->pkt.data + y * w, w);
+ break;
}
if (++(ast->sub_packet_cnt) < h)
return -1;
+ if (st->codec->codec_id == CODEC_ID_SIPR)
+ rm_reorder_sipr_data(ast);
+
ast->sub_packet_cnt = 0;
rm->audio_stream_num = st->index;
rm->audio_pkt_cnt = h * w / st->codec->block_align;
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