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libavcodec/libschroedingerdec.c

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00001 /*
00002  * Dirac decoder support via Schroedinger libraries
00003  * Copyright (c) 2008 BBC, Anuradha Suraparaju <asuraparaju at gmail dot com >
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00030 #include "avcodec.h"
00031 #include "libdirac_libschro.h"
00032 #include "libschroedinger.h"
00033 
00034 #undef NDEBUG
00035 #include <assert.h>
00036 
00037 
00038 #include <schroedinger/schro.h>
00039 #include <schroedinger/schrodebug.h>
00040 #include <schroedinger/schrovideoformat.h>
00041 
00043 typedef struct FfmpegSchroDecoderParams {
00045     SchroVideoFormat *format;
00046 
00048     SchroFrameFormat frame_format;
00049 
00051     SchroDecoder* decoder;
00052 
00054     FfmpegDiracSchroQueue dec_frame_queue;
00055 
00057     int eos_signalled;
00058 
00060     int eos_pulled;
00061 
00063     AVPicture dec_pic;
00064 } FfmpegSchroDecoderParams;
00065 
00066 typedef struct FfmpegSchroParseUnitContext {
00067     const uint8_t *buf;
00068     int           buf_size;
00069 } FfmpegSchroParseUnitContext;
00070 
00071 
00072 static void libschroedinger_decode_buffer_free(SchroBuffer *schro_buf,
00073                                                void *priv);
00074 
00075 static void FfmpegSchroParseContextInit(FfmpegSchroParseUnitContext *parse_ctx,
00076                                         const uint8_t *buf, int buf_size)
00077 {
00078     parse_ctx->buf           = buf;
00079     parse_ctx->buf_size      = buf_size;
00080 }
00081 
00082 static SchroBuffer* FfmpegFindNextSchroParseUnit(FfmpegSchroParseUnitContext *parse_ctx)
00083 {
00084     SchroBuffer *enc_buf = NULL;
00085     int next_pu_offset = 0;
00086     unsigned char *in_buf;
00087 
00088     if (parse_ctx->buf_size < 13 ||
00089         parse_ctx->buf[0] != 'B' ||
00090         parse_ctx->buf[1] != 'B' ||
00091         parse_ctx->buf[2] != 'C' ||
00092         parse_ctx->buf[3] != 'D')
00093         return NULL;
00094 
00095     next_pu_offset = (parse_ctx->buf[5] << 24) +
00096                      (parse_ctx->buf[6] << 16) +
00097                      (parse_ctx->buf[7] <<  8) +
00098                       parse_ctx->buf[8];
00099 
00100     if (next_pu_offset == 0 &&
00101         SCHRO_PARSE_CODE_IS_END_OF_SEQUENCE(parse_ctx->buf[4]))
00102         next_pu_offset = 13;
00103 
00104     if (next_pu_offset <= 0 || parse_ctx->buf_size < next_pu_offset)
00105         return NULL;
00106 
00107     in_buf = av_malloc(next_pu_offset);
00108     memcpy(in_buf, parse_ctx->buf, next_pu_offset);
00109     enc_buf       = schro_buffer_new_with_data(in_buf, next_pu_offset);
00110     enc_buf->free = libschroedinger_decode_buffer_free;
00111     enc_buf->priv = in_buf;
00112 
00113     parse_ctx->buf      += next_pu_offset;
00114     parse_ctx->buf_size -= next_pu_offset;
00115 
00116     return enc_buf;
00117 }
00118 
00122 static enum PixelFormat GetFfmpegChromaFormat(SchroChromaFormat schro_pix_fmt)
00123 {
00124     int num_formats = sizeof(ffmpeg_schro_pixel_format_map) /
00125                       sizeof(ffmpeg_schro_pixel_format_map[0]);
00126     int idx;
00127 
00128     for (idx = 0; idx < num_formats; ++idx)
00129         if (ffmpeg_schro_pixel_format_map[idx].schro_pix_fmt == schro_pix_fmt)
00130             return ffmpeg_schro_pixel_format_map[idx].ff_pix_fmt;
00131     return PIX_FMT_NONE;
00132 }
00133 
00134 static av_cold int libschroedinger_decode_init(AVCodecContext *avccontext)
00135 {
00136 
00137     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00138     /* First of all, initialize our supporting libraries. */
00139     schro_init();
00140 
00141     schro_debug_set_level(avccontext->debug);
00142     p_schro_params->decoder = schro_decoder_new();
00143     schro_decoder_set_skip_ratio(p_schro_params->decoder, 1);
00144 
00145     if (!p_schro_params->decoder)
00146         return -1;
00147 
00148     /* Initialize the decoded frame queue. */
00149     ff_dirac_schro_queue_init(&p_schro_params->dec_frame_queue);
00150     return 0;
00151 }
00152 
00153 static void libschroedinger_decode_buffer_free(SchroBuffer *schro_buf,
00154                                                void *priv)
00155 {
00156     av_freep(&priv);
00157 }
00158 
00159 static void libschroedinger_decode_frame_free(void *frame)
00160 {
00161     schro_frame_unref(frame);
00162 }
00163 
00164 static void libschroedinger_handle_first_access_unit(AVCodecContext *avccontext)
00165 {
00166     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00167     SchroDecoder *decoder = p_schro_params->decoder;
00168 
00169     p_schro_params->format = schro_decoder_get_video_format(decoder);
00170 
00171     /* Tell FFmpeg about sequence details. */
00172     if (avcodec_check_dimensions(avccontext, p_schro_params->format->width,
00173                                  p_schro_params->format->height) < 0) {
00174         av_log(avccontext, AV_LOG_ERROR, "invalid dimensions (%dx%d)\n",
00175                p_schro_params->format->width, p_schro_params->format->height);
00176         avccontext->height = avccontext->width = 0;
00177         return;
00178     }
00179     avccontext->height  = p_schro_params->format->height;
00180     avccontext->width   = p_schro_params->format->width;
00181     avccontext->pix_fmt = GetFfmpegChromaFormat(p_schro_params->format->chroma_format);
00182 
00183     if (ff_get_schro_frame_format(p_schro_params->format->chroma_format,
00184                                   &p_schro_params->frame_format) == -1) {
00185         av_log(avccontext, AV_LOG_ERROR,
00186                "This codec currently only supports planar YUV 4:2:0, 4:2:2 "
00187                "and 4:4:4 formats.\n");
00188         return;
00189     }
00190 
00191     avccontext->time_base.den = p_schro_params->format->frame_rate_numerator;
00192     avccontext->time_base.num = p_schro_params->format->frame_rate_denominator;
00193 
00194     if (!p_schro_params->dec_pic.data[0])
00195         avpicture_alloc(&p_schro_params->dec_pic,
00196                         avccontext->pix_fmt,
00197                         avccontext->width,
00198                         avccontext->height);
00199 }
00200 
00201 static int libschroedinger_decode_frame(AVCodecContext *avccontext,
00202                                         void *data, int *data_size,
00203                                         AVPacket *avpkt)
00204 {
00205     const uint8_t *buf = avpkt->data;
00206     int buf_size = avpkt->size;
00207 
00208     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00209     SchroDecoder *decoder = p_schro_params->decoder;
00210     SchroVideoFormat *format;
00211     AVPicture *picture = data;
00212     SchroBuffer *enc_buf;
00213     SchroFrame* frame;
00214     int state;
00215     int go = 1;
00216     int outer = 1;
00217     FfmpegSchroParseUnitContext parse_ctx;
00218 
00219     *data_size = 0;
00220 
00221     FfmpegSchroParseContextInit(&parse_ctx, buf, buf_size);
00222     if (!buf_size) {
00223         if (!p_schro_params->eos_signalled) {
00224             state = schro_decoder_push_end_of_stream(decoder);
00225             p_schro_params->eos_signalled = 1;
00226         }
00227     }
00228 
00229     /* Loop through all the individual parse units in the input buffer */
00230     do {
00231         if ((enc_buf = FfmpegFindNextSchroParseUnit(&parse_ctx))) {
00232             /* Push buffer into decoder. */
00233             if (SCHRO_PARSE_CODE_IS_PICTURE(enc_buf->data[4]) &&
00234                 SCHRO_PARSE_CODE_NUM_REFS(enc_buf->data[4]) > 0)
00235                 avccontext->has_b_frames = 1;
00236             state = schro_decoder_push(decoder, enc_buf);
00237             if (state == SCHRO_DECODER_FIRST_ACCESS_UNIT)
00238                 libschroedinger_handle_first_access_unit(avccontext);
00239             go = 1;
00240         } else
00241             outer = 0;
00242         format = p_schro_params->format;
00243 
00244         while (go) {
00245             /* Parse data and process result. */
00246             state = schro_decoder_wait(decoder);
00247             switch (state) {
00248             case SCHRO_DECODER_FIRST_ACCESS_UNIT:
00249                 libschroedinger_handle_first_access_unit(avccontext);
00250                 break;
00251 
00252             case SCHRO_DECODER_NEED_BITS:
00253                 /* Need more input data - stop iterating over what we have. */
00254                 go = 0;
00255                 break;
00256 
00257             case SCHRO_DECODER_NEED_FRAME:
00258                 /* Decoder needs a frame - create one and push it in. */
00259                 frame = ff_create_schro_frame(avccontext,
00260                                               p_schro_params->frame_format);
00261                 schro_decoder_add_output_picture(decoder, frame);
00262                 break;
00263 
00264             case SCHRO_DECODER_OK:
00265                 /* Pull a frame out of the decoder. */
00266                 frame = schro_decoder_pull(decoder);
00267 
00268                 if (frame)
00269                     ff_dirac_schro_queue_push_back(&p_schro_params->dec_frame_queue,
00270                                                    frame);
00271                 break;
00272             case SCHRO_DECODER_EOS:
00273                 go = 0;
00274                 p_schro_params->eos_pulled = 1;
00275                 schro_decoder_reset(decoder);
00276                 outer = 0;
00277                 break;
00278 
00279             case SCHRO_DECODER_ERROR:
00280                 return -1;
00281                 break;
00282             }
00283         }
00284     } while (outer);
00285 
00286     /* Grab next frame to be returned from the top of the queue. */
00287     frame = ff_dirac_schro_queue_pop(&p_schro_params->dec_frame_queue);
00288 
00289     if (frame) {
00290         memcpy(p_schro_params->dec_pic.data[0],
00291                frame->components[0].data,
00292                frame->components[0].length);
00293 
00294         memcpy(p_schro_params->dec_pic.data[1],
00295                frame->components[1].data,
00296                frame->components[1].length);
00297 
00298         memcpy(p_schro_params->dec_pic.data[2],
00299                frame->components[2].data,
00300                frame->components[2].length);
00301 
00302         /* Fill picture with current buffer data from Schroedinger. */
00303         avpicture_fill(picture, p_schro_params->dec_pic.data[0],
00304                        avccontext->pix_fmt,
00305                        avccontext->width, avccontext->height);
00306 
00307         *data_size = sizeof(AVPicture);
00308 
00309         /* Now free the frame resources. */
00310         libschroedinger_decode_frame_free(frame);
00311     }
00312     return buf_size;
00313 }
00314 
00315 
00316 static av_cold int libschroedinger_decode_close(AVCodecContext *avccontext)
00317 {
00318     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00319     /* Free the decoder. */
00320     schro_decoder_free(p_schro_params->decoder);
00321     av_freep(&p_schro_params->format);
00322 
00323     avpicture_free(&p_schro_params->dec_pic);
00324 
00325     /* Free data in the output frame queue. */
00326     ff_dirac_schro_queue_free(&p_schro_params->dec_frame_queue,
00327                               libschroedinger_decode_frame_free);
00328 
00329     return 0;
00330 }
00331 
00332 static void libschroedinger_flush(AVCodecContext *avccontext)
00333 {
00334     /* Got a seek request. Free the decoded frames queue and then reset
00335      * the decoder */
00336     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00337 
00338     /* Free data in the output frame queue. */
00339     ff_dirac_schro_queue_free(&p_schro_params->dec_frame_queue,
00340                               libschroedinger_decode_frame_free);
00341 
00342     ff_dirac_schro_queue_init(&p_schro_params->dec_frame_queue);
00343     schro_decoder_reset(p_schro_params->decoder);
00344     p_schro_params->eos_pulled = 0;
00345     p_schro_params->eos_signalled = 0;
00346 }
00347 
00348 AVCodec libschroedinger_decoder = {
00349     "libschroedinger",
00350     AVMEDIA_TYPE_VIDEO,
00351     CODEC_ID_DIRAC,
00352     sizeof(FfmpegSchroDecoderParams),
00353     libschroedinger_decode_init,
00354     NULL,
00355     libschroedinger_decode_close,
00356     libschroedinger_decode_frame,
00357     CODEC_CAP_DELAY,
00358     .flush = libschroedinger_flush,
00359     .long_name = NULL_IF_CONFIG_SMALL("libschroedinger Dirac 2.2"),
00360 };

Generated on Fri Sep 16 2011 17:17:38 for FFmpeg by  doxygen 1.7.1