libavcodec/libdiracdec.c

   1 /*
   2  * Dirac decoder support via libdirac library
   3  * Copyright (c) 2005 BBC, Andrew Kennedy <dirac at rd dot bbc dot co dot uk>
   4  * Copyright (c) 2006-2008 BBC, Anuradha Suraparaju <asuraparaju at gmail dot com >
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /**
  24 * @file libavcodec/libdiracdec.c
  25 * Dirac decoder support via libdirac library; more details about the Dirac
  26 * project can be found at http://dirac.sourceforge.net/.
  27 * The libdirac_decoder library implements Dirac specification version 2.2
  28 * (http://dirac.sourceforge.net/specification.html).
  29 */
  30
  31 #include "libdirac.h"
  32
  33 #undef NDEBUG
  34 #include <assert.h>
  35
  36 #include <libdirac_decoder/dirac_parser.h>
  37
  38 /** contains a single frame returned from Dirac */
  39 typedef struct FfmpegDiracDecoderParams
  40 {
  41     /** decoder handle */
  42     dirac_decoder_t* p_decoder;
  43
  44     /** buffer to hold decoded frame */
  45     unsigned char* p_out_frame_buf;
  46 } FfmpegDiracDecoderParams;
  47
  48
  49 /**
  50 * returns FFmpeg chroma format
  51 */
  52 static enum PixelFormat GetFfmpegChromaFormat(dirac_chroma_t dirac_pix_fmt)
  53 {
  54     int num_formats = sizeof(ffmpeg_dirac_pixel_format_map) /
  55                       sizeof(ffmpeg_dirac_pixel_format_map[0]);
  56     int idx;
  57
  58     for (idx = 0; idx < num_formats; ++idx) {
  59         if (ffmpeg_dirac_pixel_format_map[idx].dirac_pix_fmt == dirac_pix_fmt) {
  60             return ffmpeg_dirac_pixel_format_map[idx].ff_pix_fmt;
  61         }
  62     }
  63     return PIX_FMT_NONE;
  64 }
  65
  66 static av_cold int libdirac_decode_init(AVCodecContext *avccontext)
  67 {
  68
  69     FfmpegDiracDecoderParams *p_dirac_params = avccontext->priv_data ;
  70     p_dirac_params->p_decoder =  dirac_decoder_init(avccontext->debug);
  71
  72     if (!p_dirac_params->p_decoder)
  73         return -1;
  74
  75     return 0 ;
  76 }
  77
  78 static int libdirac_decode_frame(AVCodecContext *avccontext,
  79                                  void *data, int *data_size,
  80                                  AVPacket *avpkt)
  81 {
  82     const uint8_t *buf = avpkt->data;
  83     int buf_size = avpkt->size;
  84
  85     FfmpegDiracDecoderParams *p_dirac_params = avccontext->priv_data;
  86     AVPicture *picture = data;
  87     AVPicture pic;
  88     int pict_size;
  89     unsigned char *buffer[3];
  90
  91     *data_size = 0;
  92
  93     if (buf_size>0) {
  94         /* set data to decode into buffer */
  95         dirac_buffer (p_dirac_params->p_decoder, buf, buf+buf_size);
  96         if ((buf[4] &0x08) == 0x08 && (buf[4] & 0x03))
  97             avccontext->has_b_frames = 1;
  98     }
  99     while (1) {
 100          /* parse data and process result */
 101         DecoderState state = dirac_parse (p_dirac_params->p_decoder);
 102         switch (state)
 103         {
 104         case STATE_BUFFER:
 105             return buf_size;
 106
 107         case STATE_SEQUENCE:
 108         {
 109             /* tell FFmpeg about sequence details */
 110             dirac_sourceparams_t *src_params =
 111                                   &p_dirac_params->p_decoder->src_params;
 112
 113             if (avcodec_check_dimensions(avccontext, src_params->width,
 114                                          src_params->height) < 0) {
 115                 av_log(avccontext, AV_LOG_ERROR, "Invalid dimensions (%dx%d)\n",
 116                        src_params->width, src_params->height);
 117                 avccontext->height = avccontext->width = 0;
 118                 return -1;
 119             }
 120
 121             avccontext->height = src_params->height;
 122             avccontext->width  = src_params->width;
 123
 124             avccontext->pix_fmt = GetFfmpegChromaFormat(src_params->chroma);
 125             if (avccontext->pix_fmt == PIX_FMT_NONE) {
 126                 av_log (avccontext, AV_LOG_ERROR,
 127                         "Dirac chroma format %d not supported currently\n",
 128                         src_params->chroma);
 129                 return -1;
 130             }
 131
 132             avccontext->time_base.den = src_params->frame_rate.numerator;
 133             avccontext->time_base.num = src_params->frame_rate.denominator;
 134
 135             /* calculate output dimensions */
 136             avpicture_fill(&pic, NULL, avccontext->pix_fmt,
 137                            avccontext->width, avccontext->height);
 138
 139             pict_size = avpicture_get_size(avccontext->pix_fmt,
 140                                            avccontext->width,
 141                                            avccontext->height);
 142
 143             /* allocate output buffer */
 144             if (p_dirac_params->p_out_frame_buf == NULL)
 145                 p_dirac_params->p_out_frame_buf = av_malloc (pict_size);
 146             buffer[0] = p_dirac_params->p_out_frame_buf;
 147             buffer[1] = p_dirac_params->p_out_frame_buf +
 148                         pic.linesize[0] * avccontext->height;
 149             buffer[2] = buffer[1] +
 150                         pic.linesize[1] * src_params->chroma_height;
 151
 152             /* tell Dirac about output destination */
 153             dirac_set_buf(p_dirac_params->p_decoder, buffer, NULL);
 154             break;
 155         }
 156         case STATE_SEQUENCE_END:
 157             break;
 158
 159         case STATE_PICTURE_AVAIL:
 160             /* fill picture with current buffer data from Dirac */
 161             avpicture_fill(picture, p_dirac_params->p_out_frame_buf,
 162                            avccontext->pix_fmt,
 163                            avccontext->width, avccontext->height);
 164             *data_size = sizeof(AVPicture);
 165             return buf_size;
 166
 167         case STATE_INVALID:
 168             return -1;
 169
 170         default:
 171             break;
 172         }
 173     }
 174
 175     return buf_size;
 176 }
 177
 178
 179 static av_cold int libdirac_decode_close(AVCodecContext *avccontext)
 180 {
 181     FfmpegDiracDecoderParams *p_dirac_params = avccontext->priv_data;
 182     dirac_decoder_close (p_dirac_params->p_decoder);
 183
 184     av_freep(&p_dirac_params->p_out_frame_buf);
 185
 186     return 0 ;
 187 }
 188
 189 static void libdirac_flush (AVCodecContext *avccontext)
 190 {
 191     /* Got a seek request. We will need free memory held in the private
 192      * context and free the current Dirac decoder handle and then open
 193      * a new decoder handle. */
 194     libdirac_decode_close (avccontext);
 195     libdirac_decode_init (avccontext);
 196     return;
 197 }
 198
 199
 200
 201 AVCodec libdirac_decoder = {
 202     "libdirac",
 203     CODEC_TYPE_VIDEO,
 204     CODEC_ID_DIRAC,
 205     sizeof(FfmpegDiracDecoderParams),
 206     libdirac_decode_init,
 207     NULL,
 208     libdirac_decode_close,
 209     libdirac_decode_frame,
 210     CODEC_CAP_DELAY,
 211     .flush = libdirac_flush,
 212     .long_name = NULL_IF_CONFIG_SMALL("libdirac Dirac 2.2"),
 213 } ;