Dirac decoding/encoding support via libdirac.

patch by Anuradha Suraparaju, anuradha rd.bbc.co uk

Originally committed as revision 13042 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 208 insertions, 0 deletions

diff --git a/libavcodec/libdiracdec.c b/libavcodec/libdiracdec.c
new file mode 100644
index 0000000000..5054a1cf1a
--- /dev/null
+++ b/libavcodec/libdiracdec.c
@@ -0,0 +1,208 @@
+/*
+ * Dirac decoder support via libdirac library
+ * Copyright (c) 2005 BBC, Andrew Kennedy <dirac at rd dot bbc dot co dot uk>
+ * Copyright (c) 2006-2008 BBC, Anuradha Suraparaju <asuraparaju at gmail dot com >
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+* @file libdiracdec.c
+* Dirac decoder support via libdirac library; more details about the Dirac
+* project can be found at http://dirac.sourceforge.net/.
+* The libdirac_decoder library implements Dirac specification version 2.2
+* (http://dirac.sourceforge.net/specification.html).
+*/
+
+#include "libdirac.h"
+
+#undef NDEBUG
+#include <assert.h>
+
+#include <libdirac_decoder/dirac_parser.h>
+
+/** contains a single frame returned from Dirac */
+typedef struct FfmpegDiracDecoderParams
+{
+    /** decoder handle */
+    dirac_decoder_t* p_decoder;
+
+    /** buffer to hold decoded frame */
+    unsigned char* p_out_frame_buf;
+} FfmpegDiracDecoderParams;
+
+
+/**
+* returns FFmpeg chroma format
+*/
+static enum PixelFormat GetFfmpegChromaFormat(dirac_chroma_t dirac_pix_fmt)
+{
+    int num_formats = sizeof(ffmpeg_dirac_pixel_format_map) /
+                      sizeof(ffmpeg_dirac_pixel_format_map[0]);
+    int idx;
+
+    for (idx = 0; idx < num_formats; ++idx) {
+        if (ffmpeg_dirac_pixel_format_map[idx].dirac_pix_fmt == dirac_pix_fmt) {
+            return ffmpeg_dirac_pixel_format_map[idx].ff_pix_fmt;
+        }
+    }
+    return PIX_FMT_NONE;
+}
+
+static int libdirac_decode_init(AVCodecContext *avccontext)
+{
+
+    FfmpegDiracDecoderParams *p_dirac_params = avccontext->priv_data ;
+    p_dirac_params->p_decoder =  dirac_decoder_init(avccontext->debug);
+
+    if (!p_dirac_params->p_decoder)
+        return -1;
+
+    return 0 ;
+}
+
+static int libdirac_decode_frame(AVCodecContext *avccontext,
+                                 void *data, int *data_size,
+                                 const uint8_t *buf, int buf_size)
+{
+
+    FfmpegDiracDecoderParams *p_dirac_params = avccontext->priv_data;
+    AVPicture *picture = data;
+    AVPicture pic;
+    int pict_size;
+    unsigned char *buffer[3];
+
+    *data_size = 0;
+
+    if (buf_size>0)
+        /* set data to decode into buffer */
+        dirac_buffer (p_dirac_params->p_decoder, buf, buf+buf_size);
+
+    while (1) {
+         /* parse data and process result */
+        DecoderState state = dirac_parse (p_dirac_params->p_decoder);
+        switch (state)
+        {
+        case STATE_BUFFER:
+            return buf_size;
+
+        case STATE_SEQUENCE:
+        {
+            /* tell FFmpeg about sequence details */
+            dirac_sourceparams_t *src_params =
+                                  &p_dirac_params->p_decoder->src_params;
+
+            if (avcodec_check_dimensions(avccontext, src_params->width,
+                                         src_params->height) < 0) {
+                av_log(avccontext, AV_LOG_ERROR, "Invalid dimensions (%dx%d)\n",
+                       src_params->width, src_params->height);
+                avccontext->height = avccontext->width = 0;
+                return -1;
+            }
+
+            avccontext->height = src_params->height;
+            avccontext->width  = src_params->width;
+
+            avccontext->pix_fmt = GetFfmpegChromaFormat(src_params->chroma);
+            if (avccontext->pix_fmt == PIX_FMT_NONE) {
+                av_log (avccontext, AV_LOG_ERROR,
+                        "Dirac chroma format %d not supported currently\n",
+                        src_params->chroma);
+                return -1;
+            }
+
+            avccontext->time_base.den = src_params->frame_rate.numerator;
+            avccontext->time_base.num = src_params->frame_rate.denominator;
+
+            /* calculate output dimensions */
+            avpicture_fill(&pic, NULL, avccontext->pix_fmt,
+                           avccontext->width, avccontext->height);
+
+            pict_size = avpicture_get_size(avccontext->pix_fmt,
+                                           avccontext->width,
+                                           avccontext->height);
+
+            /* allocate output buffer */
+            if (p_dirac_params->p_out_frame_buf == NULL)
+                p_dirac_params->p_out_frame_buf = av_malloc (pict_size);
+            buffer[0] = p_dirac_params->p_out_frame_buf;
+            buffer[1] = p_dirac_params->p_out_frame_buf +
+                        pic.linesize[0] * avccontext->height;
+            buffer[2] = buffer[1] +
+                        pic.linesize[1] * src_params->chroma_height;
+
+            /* tell Dirac about output destination */
+            dirac_set_buf(p_dirac_params->p_decoder, buffer, NULL);
+            break;
+        }
+        case STATE_SEQUENCE_END:
+            break;
+
+        case STATE_PICTURE_AVAIL:
+            /* fill picture with current buffer data from Dirac */
+            avpicture_fill(picture, p_dirac_params->p_out_frame_buf,
+                           avccontext->pix_fmt,
+                           avccontext->width, avccontext->height);
+            *data_size = sizeof(AVPicture);
+            return buf_size;
+
+        case STATE_INVALID:
+            return -1;
+
+        default:
+            break;
+        }
+    }
+
+    return buf_size;
+}
+
+
+static int libdirac_decode_close(AVCodecContext *avccontext)
+{
+    FfmpegDiracDecoderParams *p_dirac_params = avccontext->priv_data;
+    dirac_decoder_close (p_dirac_params->p_decoder);
+
+    av_freep(&p_dirac_params->p_out_frame_buf);
+
+    return 0 ;
+}
+
+static void libdirac_flush (AVCodecContext *avccontext)
+{
+    /* Got a seek request. We will need free memory held in the private
+     * context and free the current Dirac decoder handle and then open
+     * a new decoder handle. */
+    libdirac_decode_close (avccontext);
+    libdirac_decode_init (avccontext);
+    return;
+}
+
+
+
+AVCodec libdirac_decoder = {
+    "libdirac",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_DIRAC,
+    sizeof(FfmpegDiracDecoderParams),
+    libdirac_decode_init,
+    NULL,
+    libdirac_decode_close,
+    libdirac_decode_frame,
+    CODEC_CAP_DELAY,
+    .flush = libdirac_flush
+} ;