lavc: export Dirac parsing API used by the ogg demuxer as public

Also, stop using AVCodecContext for storing the stream parameters.

configure

@@ -1646,6 +1646,7 @@ CONFIG_EXTRA="
     blockdsp
     bswapdsp
     cabac
+    dirac_parse
     dvprofile
     faandct
     faanidct
@@ -1850,6 +1851,7 @@ threads_if_any="$THREADS_LIST"
 
 # subsystems
 dct_select="rdft"
+dirac_parse_select="golomb"
 error_resilience_select="me_cmp"
 faandct_deps="faan fdctdsp"
 faanidct_deps="faan idctdsp"
@@ -2241,7 +2243,7 @@ mxf_d10_muxer_select="mxf_muxer"
 nut_muxer_select="riffenc"
 nuv_demuxer_select="riffdec"
 oga_muxer_select="ogg_muxer"
-ogg_demuxer_select="golomb"
+ogg_demuxer_select="dirac_parse"
 opus_muxer_select="ogg_muxer"
 psp_muxer_select="mov_muxer"
 rtp_demuxer_select="sdp_demuxer"

doc/APIchanges

@@ -13,10 +13,12 @@ libavutil:     2015-08-28
 
 API changes, most recent first:
 
-2015-xx-xx - xxxxxxx - lavc 57.11.0 - avcodec.h
+2015-xx-xx - xxxxxxx - lavc 57.11.0 - avcodec.h dirac.h
   xxxxxxx - Add av_packet_add_side_data().
   xxxxxxx - Add AVCodecContext.coded_side_data.
   xxxxxxx - Add AVCPBProperties API.
+  xxxxxxx - Add a new public header dirac.h containing
+            av_dirac_parse_sequence_header()
 
 2015-xx-xx - xxxxxxx - lavc 57.9.1 - avcodec.h
   Deprecate rtp_callback without replacement, i.e. it won't be possible to

libavcodec/Makefile

@@ -4,6 +4,7 @@ HEADERS = avcodec.h                                                     \
           avfft.h                                                       \
           dv_profile.h                                                  \
           d3d11va.h                                                     \
+          dirac.h                                                       \
           dxva2.h                                                       \
           qsv.h                                                         \
           vaapi.h                                                       \
@@ -20,6 +21,7 @@ OBJS = allcodecs.o                                                      \
        bitstream_filter.o                                               \
        codec_desc.o                                                     \
        d3d11va.o                                                        \
+       dirac.o                                                          \
        dv_profile.o                                                     \
        imgconvert.o                                                     \
        log2_tab.o                                                       \

libavcodec/dirac.h

@@ -29,9 +29,8 @@
  */
 
 #include "avcodec.h"
-#include "get_bits.h"
 
-typedef struct dirac_source_params {
+typedef struct AVDiracSeqHeader {
     unsigned width;
     unsigned height;
     uint8_t chroma_format;          ///< 0: 444  1: 422  2: 420
@@ -49,9 +48,33 @@ typedef struct dirac_source_params {
 
     uint8_t pixel_range_index;      ///< index into dirac_pixel_range_presets[]
     uint8_t color_spec_index;       ///< index into dirac_color_spec_presets[]
-} dirac_source_params;
 
-int avpriv_dirac_parse_sequence_header(AVCodecContext *avctx, GetBitContext *gb,
-                                       dirac_source_params *source);
+    int profile;
+    int level;
+
+    AVRational framerate;
+    AVRational sample_aspect_ratio;
+
+    enum AVPixelFormat pix_fmt;
+    enum AVColorRange color_range;
+    enum AVColorPrimaries color_primaries;
+    enum AVColorTransferCharacteristic color_trc;
+    enum AVColorSpace colorspace;
+} AVDiracSeqHeader;
+
+/**
+ * Parse a Dirac sequence header.
+ *
+ * @param dsh this function will allocate and fill an AVDiracSeqHeader struct
+ *            and write it into this pointer. The caller must free it with
+ *            av_free().
+ * @param buf the data buffer
+ * @param buf_size the size of the data buffer in bytes
+ * @param log_ctx if non-NULL, this function will log errors here
+ * @return 0 on success, a negative AVERROR code on failure
+ */
+int av_dirac_parse_sequence_header(AVDiracSeqHeader **dsh,
+                                   const uint8_t *buf, size_t buf_size,
+                                   void *log_ctx);
 
 #endif /* AVCODEC_DIRAC_H */

libavformat/oggparsedirac.c

@@ -18,7 +18,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include "libavcodec/get_bits.h"
+#include "libavutil/intreadwrite.h"
 #include "libavcodec/dirac.h"
 #include "avformat.h"
 #include "internal.h"
@@ -29,21 +29,34 @@ static int dirac_header(AVFormatContext *s, int idx)
     struct ogg *ogg = s->priv_data;
     struct ogg_stream *os = ogg->streams + idx;
     AVStream *st = s->streams[idx];
-    dirac_source_params source;
-    GetBitContext gb;
+    AVDiracSeqHeader *dsh;
+    int ret;
 
     // already parsed the header
     if (st->codec->codec_id == AV_CODEC_ID_DIRAC)
         return 0;
 
-    init_get_bits(&gb, os->buf + os->pstart + 13, (os->psize - 13) * 8);
-    if (avpriv_dirac_parse_sequence_header(st->codec, &gb, &source) < 0)
-        return -1;
+    ret = av_dirac_parse_sequence_header(&dsh, os->buf + os->pstart + 13, (os->psize - 13) * 8, s);
+    if (ret < 0)
+        return ret;
+
+    st->codec->codec_type      = AVMEDIA_TYPE_VIDEO;
+    st->codec->codec_id        = AV_CODEC_ID_DIRAC;
+    st->codec->width           = dsh->width;
+    st->codec->height          = dsh->height;
+    st->codec->pix_fmt         = dsh->pix_fmt;
+    st->codec->color_range     = dsh->color_range;
+    st->codec->color_trc       = dsh->color_trc;
+    st->codec->color_primaries = dsh->color_primaries;
+    st->codec->colorspace      = dsh->colorspace;
+    st->codec->profile         = dsh->profile;
+    st->codec->level           = dsh->level;
 
-    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
-    st->codec->codec_id = AV_CODEC_ID_DIRAC;
     // dirac in ogg always stores timestamps as though the video were interlaced
-    avpriv_set_pts_info(st, 64, st->codec->time_base.num, 2*st->codec->time_base.den);
+    avpriv_set_pts_info(st, 64, dsh->framerate.den, 2 * dsh->framerate.num);
+
+    av_freep(&dsh);
+
     return 1;
 }