shorten decoder by (Jeff Muizelaar <jrmuizel gmail com>)

Originally committed as revision 3984 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/allcodecs.c

@@ -194,6 +194,7 @@ void avcodec_register_all(void)
     register_avcodec(&sol_dpcm_decoder);
     register_avcodec(&qtrle_decoder);
     register_avcodec(&flac_decoder);
+    register_avcodec(&shorten_decoder);
 #endif /* CONFIG_DECODERS */
 
 #ifdef AMR_NB

libavcodec/avcodec.h

@@ -164,6 +164,7 @@ enum CodecID {
     CODEC_ID_FLAC,
     CODEC_ID_MP3ADU,
     CODEC_ID_MP3ON4,
+    CODEC_ID_SHORTEN,
     
     CODEC_ID_OGGTHEORA= 0x16000, 
     
@@ -2008,6 +2009,7 @@ extern AVCodec ulti_decoder;
 extern AVCodec qdraw_decoder;
 extern AVCodec xl_decoder;
 extern AVCodec qpeg_decoder;
+extern AVCodec shorten_decoder;
 
 /* pcm codecs */
 #define PCM_CODEC(id, name) \

libavcodec/golomb.h

@@ -284,6 +284,27 @@ static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int es
     return (v>>1) ^ -(v&1);
 }
 
+/**
+ * read unsigned golomb rice code (shorten).
+ */
+static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){
+	return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
+}
+
+/**
+ * read signed golomb rice code (shorten).
+ */
+static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
+{
+    int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
+    if (uvar & 1)
+        return ~(uvar >> 1);
+    else
+        return uvar >> 1;
+}
+
+
+
 #ifdef TRACE
 
 static inline int get_ue(GetBitContext *s, char *file, const char *func, int line){

libavformat/raw.c

@@ -188,6 +188,21 @@ static int ac3_read_header(AVFormatContext *s,
     return 0;
 }
 
+static int shorten_read_header(AVFormatContext *s,
+                               AVFormatParameters *ap)
+{
+    AVStream *st;
+
+    st = av_new_stream(s, 0);
+    if (!st)
+        return AVERROR_NOMEM;
+    st->codec.codec_type = CODEC_TYPE_AUDIO;
+    st->codec.codec_id = CODEC_ID_SHORTEN;
+    st->need_parsing = 1;
+    /* the parameters will be extracted from the compressed bitstream */
+    return 0;
+}
+
 /* dts read */
 static int dts_read_header(AVFormatContext *s,
                            AVFormatParameters *ap)
@@ -295,6 +310,17 @@ static int h261_probe(AVProbeData *p)
     return 0;
 }
 
+AVInputFormat shorten_iformat = {
+    "shn",
+    "raw shn",
+    0,
+    NULL,
+    shorten_read_header,
+    raw_read_partial_packet,
+    raw_read_close,
+    .extensions = "shn",
+};
+
 AVInputFormat ac3_iformat = {
     "ac3",
     "raw ac3",
@@ -672,6 +698,9 @@ AVOutputFormat null_oformat = {
 
 int raw_init(void)
 {
+
+    av_register_input_format(&shorten_iformat);
+
     av_register_input_format(&ac3_iformat);
     av_register_output_format(&ac3_oformat);
 

libavformat/utils.c

@@ -1845,6 +1845,7 @@ int av_find_stream_info(AVFormatContext *ic)
              st->codec.codec_id == CODEC_ID_PGMYUV ||
              st->codec.codec_id == CODEC_ID_PBM ||
              st->codec.codec_id == CODEC_ID_PPM ||
+             st->codec.codec_id == CODEC_ID_SHORTEN ||
              (st->codec.codec_id == CODEC_ID_MPEG4 && !st->need_parsing)))
             try_decode_frame(st, pkt->data, pkt->size);