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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 "libavutil/imgutils.h"
00031 #include "avcodec.h"
00032 #include "libdirac_libschro.h"
00033 #include "libschroedinger.h"
00034 
00035 #undef NDEBUG
00036 #include <assert.h>
00037 
00038 
00039 #include <schroedinger/schro.h>
00040 #include <schroedinger/schrodebug.h>
00041 #include <schroedinger/schrovideoformat.h>
00042 
00044 typedef struct FfmpegSchroDecoderParams {
00046     SchroVideoFormat *format;
00047 
00049     SchroFrameFormat frame_format;
00050 
00052     SchroDecoder* decoder;
00053 
00055     FfmpegDiracSchroQueue dec_frame_queue;
00056 
00058     int eos_signalled;
00059 
00061     int eos_pulled;
00062 
00064     AVPicture dec_pic;
00065 } FfmpegSchroDecoderParams;
00066 
00067 typedef struct FfmpegSchroParseUnitContext {
00068     const uint8_t *buf;
00069     int           buf_size;
00070 } FfmpegSchroParseUnitContext;
00071 
00072 
00073 static void libschroedinger_decode_buffer_free(SchroBuffer *schro_buf,
00074                                                void *priv);
00075 
00076 static void FfmpegSchroParseContextInit(FfmpegSchroParseUnitContext *parse_ctx,
00077                                         const uint8_t *buf, int buf_size)
00078 {
00079     parse_ctx->buf           = buf;
00080     parse_ctx->buf_size      = buf_size;
00081 }
00082 
00083 static SchroBuffer* FfmpegFindNextSchroParseUnit(FfmpegSchroParseUnitContext *parse_ctx)
00084 {
00085     SchroBuffer *enc_buf = NULL;
00086     int next_pu_offset = 0;
00087     unsigned char *in_buf;
00088 
00089     if (parse_ctx->buf_size < 13 ||
00090         parse_ctx->buf[0] != 'B' ||
00091         parse_ctx->buf[1] != 'B' ||
00092         parse_ctx->buf[2] != 'C' ||
00093         parse_ctx->buf[3] != 'D')
00094         return NULL;
00095 
00096     next_pu_offset = (parse_ctx->buf[5] << 24) +
00097                      (parse_ctx->buf[6] << 16) +
00098                      (parse_ctx->buf[7] <<  8) +
00099                       parse_ctx->buf[8];
00100 
00101     if (next_pu_offset == 0 &&
00102         SCHRO_PARSE_CODE_IS_END_OF_SEQUENCE(parse_ctx->buf[4]))
00103         next_pu_offset = 13;
00104 
00105     if (next_pu_offset <= 0 || parse_ctx->buf_size < next_pu_offset)
00106         return NULL;
00107 
00108     in_buf = av_malloc(next_pu_offset);
00109     memcpy(in_buf, parse_ctx->buf, next_pu_offset);
00110     enc_buf       = schro_buffer_new_with_data(in_buf, next_pu_offset);
00111     enc_buf->free = libschroedinger_decode_buffer_free;
00112     enc_buf->priv = in_buf;
00113 
00114     parse_ctx->buf      += next_pu_offset;
00115     parse_ctx->buf_size -= next_pu_offset;
00116 
00117     return enc_buf;
00118 }
00119 
00123 static enum PixelFormat GetFfmpegChromaFormat(SchroChromaFormat schro_pix_fmt)
00124 {
00125     int num_formats = sizeof(ffmpeg_schro_pixel_format_map) /
00126                       sizeof(ffmpeg_schro_pixel_format_map[0]);
00127     int idx;
00128 
00129     for (idx = 0; idx < num_formats; ++idx)
00130         if (ffmpeg_schro_pixel_format_map[idx].schro_pix_fmt == schro_pix_fmt)
00131             return ffmpeg_schro_pixel_format_map[idx].ff_pix_fmt;
00132     return PIX_FMT_NONE;
00133 }
00134 
00135 static av_cold int libschroedinger_decode_init(AVCodecContext *avccontext)
00136 {
00137 
00138     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00139     /* First of all, initialize our supporting libraries. */
00140     schro_init();
00141 
00142     schro_debug_set_level(avccontext->debug);
00143     p_schro_params->decoder = schro_decoder_new();
00144     schro_decoder_set_skip_ratio(p_schro_params->decoder, 1);
00145 
00146     if (!p_schro_params->decoder)
00147         return -1;
00148 
00149     /* Initialize the decoded frame queue. */
00150     ff_dirac_schro_queue_init(&p_schro_params->dec_frame_queue);
00151     return 0;
00152 }
00153 
00154 static void libschroedinger_decode_buffer_free(SchroBuffer *schro_buf,
00155                                                void *priv)
00156 {
00157     av_freep(&priv);
00158 }
00159 
00160 static void libschroedinger_decode_frame_free(void *frame)
00161 {
00162     schro_frame_unref(frame);
00163 }
00164 
00165 static void libschroedinger_handle_first_access_unit(AVCodecContext *avccontext)
00166 {
00167     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00168     SchroDecoder *decoder = p_schro_params->decoder;
00169 
00170     p_schro_params->format = schro_decoder_get_video_format(decoder);
00171 
00172     /* Tell FFmpeg about sequence details. */
00173     if (av_image_check_size(p_schro_params->format->width, p_schro_params->format->height,
00174                             0, avccontext) < 0) {
00175         av_log(avccontext, AV_LOG_ERROR, "invalid dimensions (%dx%d)\n",
00176                p_schro_params->format->width, p_schro_params->format->height);
00177         avccontext->height = avccontext->width = 0;
00178         return;
00179     }
00180     avccontext->height  = p_schro_params->format->height;
00181     avccontext->width   = p_schro_params->format->width;
00182     avccontext->pix_fmt = GetFfmpegChromaFormat(p_schro_params->format->chroma_format);
00183 
00184     if (ff_get_schro_frame_format(p_schro_params->format->chroma_format,
00185                                   &p_schro_params->frame_format) == -1) {
00186         av_log(avccontext, AV_LOG_ERROR,
00187                "This codec currently only supports planar YUV 4:2:0, 4:2:2 "
00188                "and 4:4:4 formats.\n");
00189         return;
00190     }
00191 
00192     avccontext->time_base.den = p_schro_params->format->frame_rate_numerator;
00193     avccontext->time_base.num = p_schro_params->format->frame_rate_denominator;
00194 
00195     if (!p_schro_params->dec_pic.data[0])
00196         avpicture_alloc(&p_schro_params->dec_pic,
00197                         avccontext->pix_fmt,
00198                         avccontext->width,
00199                         avccontext->height);
00200 }
00201 
00202 static int libschroedinger_decode_frame(AVCodecContext *avccontext,
00203                                         void *data, int *data_size,
00204                                         AVPacket *avpkt)
00205 {
00206     const uint8_t *buf = avpkt->data;
00207     int buf_size = avpkt->size;
00208 
00209     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00210     SchroDecoder *decoder = p_schro_params->decoder;
00211     SchroVideoFormat *format;
00212     AVPicture *picture = data;
00213     SchroBuffer *enc_buf;
00214     SchroFrame* frame;
00215     int state;
00216     int go = 1;
00217     int outer = 1;
00218     FfmpegSchroParseUnitContext parse_ctx;
00219 
00220     *data_size = 0;
00221 
00222     FfmpegSchroParseContextInit(&parse_ctx, buf, buf_size);
00223     if (!buf_size) {
00224         if (!p_schro_params->eos_signalled) {
00225             state = schro_decoder_push_end_of_stream(decoder);
00226             p_schro_params->eos_signalled = 1;
00227         }
00228     }
00229 
00230     /* Loop through all the individual parse units in the input buffer */
00231     do {
00232         if ((enc_buf = FfmpegFindNextSchroParseUnit(&parse_ctx))) {
00233             /* Push buffer into decoder. */
00234             if (SCHRO_PARSE_CODE_IS_PICTURE(enc_buf->data[4]) &&
00235                 SCHRO_PARSE_CODE_NUM_REFS(enc_buf->data[4]) > 0)
00236                 avccontext->has_b_frames = 1;
00237             state = schro_decoder_push(decoder, enc_buf);
00238             if (state == SCHRO_DECODER_FIRST_ACCESS_UNIT)
00239                 libschroedinger_handle_first_access_unit(avccontext);
00240             go = 1;
00241         } else
00242             outer = 0;
00243         format = p_schro_params->format;
00244 
00245         while (go) {
00246             /* Parse data and process result. */
00247             state = schro_decoder_wait(decoder);
00248             switch (state) {
00249             case SCHRO_DECODER_FIRST_ACCESS_UNIT:
00250                 libschroedinger_handle_first_access_unit(avccontext);
00251                 break;
00252 
00253             case SCHRO_DECODER_NEED_BITS:
00254                 /* Need more input data - stop iterating over what we have. */
00255                 go = 0;
00256                 break;
00257 
00258             case SCHRO_DECODER_NEED_FRAME:
00259                 /* Decoder needs a frame - create one and push it in. */
00260                 frame = ff_create_schro_frame(avccontext,
00261                                               p_schro_params->frame_format);
00262                 schro_decoder_add_output_picture(decoder, frame);
00263                 break;
00264 
00265             case SCHRO_DECODER_OK:
00266                 /* Pull a frame out of the decoder. */
00267                 frame = schro_decoder_pull(decoder);
00268 
00269                 if (frame)
00270                     ff_dirac_schro_queue_push_back(&p_schro_params->dec_frame_queue,
00271                                                    frame);
00272                 break;
00273             case SCHRO_DECODER_EOS:
00274                 go = 0;
00275                 p_schro_params->eos_pulled = 1;
00276                 schro_decoder_reset(decoder);
00277                 outer = 0;
00278                 break;
00279 
00280             case SCHRO_DECODER_ERROR:
00281                 return -1;
00282                 break;
00283             }
00284         }
00285     } while (outer);
00286 
00287     /* Grab next frame to be returned from the top of the queue. */
00288     frame = ff_dirac_schro_queue_pop(&p_schro_params->dec_frame_queue);
00289 
00290     if (frame) {
00291         memcpy(p_schro_params->dec_pic.data[0],
00292                frame->components[0].data,
00293                frame->components[0].length);
00294 
00295         memcpy(p_schro_params->dec_pic.data[1],
00296                frame->components[1].data,
00297                frame->components[1].length);
00298 
00299         memcpy(p_schro_params->dec_pic.data[2],
00300                frame->components[2].data,
00301                frame->components[2].length);
00302 
00303         /* Fill picture with current buffer data from Schroedinger. */
00304         avpicture_fill(picture, p_schro_params->dec_pic.data[0],
00305                        avccontext->pix_fmt,
00306                        avccontext->width, avccontext->height);
00307 
00308         *data_size = sizeof(AVPicture);
00309 
00310         /* Now free the frame resources. */
00311         libschroedinger_decode_frame_free(frame);
00312     }
00313     return buf_size;
00314 }
00315 
00316 
00317 static av_cold int libschroedinger_decode_close(AVCodecContext *avccontext)
00318 {
00319     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00320     /* Free the decoder. */
00321     schro_decoder_free(p_schro_params->decoder);
00322     av_freep(&p_schro_params->format);
00323 
00324     avpicture_free(&p_schro_params->dec_pic);
00325 
00326     /* Free data in the output frame queue. */
00327     ff_dirac_schro_queue_free(&p_schro_params->dec_frame_queue,
00328                               libschroedinger_decode_frame_free);
00329 
00330     return 0;
00331 }
00332 
00333 static void libschroedinger_flush(AVCodecContext *avccontext)
00334 {
00335     /* Got a seek request. Free the decoded frames queue and then reset
00336      * the decoder */
00337     FfmpegSchroDecoderParams *p_schro_params = avccontext->priv_data;
00338 
00339     /* Free data in the output frame queue. */
00340     ff_dirac_schro_queue_free(&p_schro_params->dec_frame_queue,
00341                               libschroedinger_decode_frame_free);
00342 
00343     ff_dirac_schro_queue_init(&p_schro_params->dec_frame_queue);
00344     schro_decoder_reset(p_schro_params->decoder);
00345     p_schro_params->eos_pulled = 0;
00346     p_schro_params->eos_signalled = 0;
00347 }
00348 
00349 AVCodec ff_libschroedinger_decoder = {
00350     "libschroedinger",
00351     AVMEDIA_TYPE_VIDEO,
00352     CODEC_ID_DIRAC,
00353     sizeof(FfmpegSchroDecoderParams),
00354     libschroedinger_decode_init,
00355     NULL,
00356     libschroedinger_decode_close,
00357     libschroedinger_decode_frame,
00358     CODEC_CAP_DELAY,
00359     .flush = libschroedinger_flush,
00360     .long_name = NULL_IF_CONFIG_SMALL("libschroedinger Dirac 2.2"),
00361 };

Generated on Wed Apr 11 2012 07:31:33 for FFmpeg by  doxygen 1.7.1