/*
  * Dirac decoder support via Schroedinger libraries
  * Copyright (c) 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

 * Dirac decoder support via libschroedinger-1.0 libraries. More details about
 * the Schroedinger project can be found at http://www.diracvideo.org/.
 * The library implements Dirac Specification Version 2.2.
 * (http://dirac.sourceforge.net/specification.html).
 */
 

 #include "libavutil/imgutils.h"

 #include "avcodec.h"
 #include "libdirac_libschro.h"
 #include "libschroedinger.h"
 
 #undef NDEBUG
 #include <assert.h>
 
 
 #include <schroedinger/schro.h>
 #include <schroedinger/schrodebug.h>
 #include <schroedinger/schrovideoformat.h>
 
 /** libschroedinger decoder private data */

 typedef struct SchroDecoderParams {

     /** Schroedinger video format */
     SchroVideoFormat *format;
 
     /** Schroedinger frame format */
     SchroFrameFormat frame_format;
 
     /** decoder handle */
     SchroDecoder* decoder;
 
     /** queue storing decoded frames */

     DiracSchroQueue dec_frame_queue;

 
     /** end of sequence signalled */
     int eos_signalled;
 
     /** end of sequence pulled */
     int eos_pulled;
 
     /** decoded picture */
     AVPicture dec_pic;

 } SchroDecoderParams;

 typedef struct SchroParseUnitContext {

     const uint8_t *buf;
     int           buf_size;

 } SchroParseUnitContext;

 static void libschroedinger_decode_buffer_free(SchroBuffer *schro_buf,
                                                void *priv);

 static void SchroParseContextInit(SchroParseUnitContext *parse_ctx,
                                   const uint8_t *buf, int buf_size)

 {
     parse_ctx->buf           = buf;
     parse_ctx->buf_size      = buf_size;
 }
 

 static SchroBuffer *FindNextSchroParseUnit(SchroParseUnitContext *parse_ctx)

 {
     SchroBuffer *enc_buf = NULL;
     int next_pu_offset = 0;
     unsigned char *in_buf;
 
     if (parse_ctx->buf_size < 13 ||
         parse_ctx->buf[0] != 'B' ||
         parse_ctx->buf[1] != 'B' ||
         parse_ctx->buf[2] != 'C' ||
         parse_ctx->buf[3] != 'D')
         return NULL;
 
     next_pu_offset = (parse_ctx->buf[5] << 24) +
                      (parse_ctx->buf[6] << 16) +
                      (parse_ctx->buf[7] <<  8) +
                       parse_ctx->buf[8];
 
     if (next_pu_offset == 0 &&
         SCHRO_PARSE_CODE_IS_END_OF_SEQUENCE(parse_ctx->buf[4]))
         next_pu_offset = 13;
 
     if (next_pu_offset <= 0 || parse_ctx->buf_size < next_pu_offset)
         return NULL;
 
     in_buf = av_malloc(next_pu_offset);

     memcpy(in_buf, parse_ctx->buf, next_pu_offset);
     enc_buf       = schro_buffer_new_with_data(in_buf, next_pu_offset);

     enc_buf->free = libschroedinger_decode_buffer_free;
     enc_buf->priv = in_buf;
 

     parse_ctx->buf      += next_pu_offset;

     parse_ctx->buf_size -= next_pu_offset;
 
     return enc_buf;
 }
 

 /**

 * Returns FFmpeg chroma format.

 */

 static enum PixelFormat get_chroma_format(SchroChromaFormat schro_pix_fmt)

 {

     int num_formats = sizeof(schro_pixel_format_map) /
                       sizeof(schro_pixel_format_map[0]);

     int idx;
 

     for (idx = 0; idx < num_formats; ++idx)

         if (schro_pixel_format_map[idx].schro_pix_fmt == schro_pix_fmt)
             return schro_pixel_format_map[idx].ff_pix_fmt;

     return PIX_FMT_NONE;
 }
 

 static av_cold int libschroedinger_decode_init(AVCodecContext *avccontext)

 {
 

     SchroDecoderParams *p_schro_params = avccontext->priv_data;

     /* First of all, initialize our supporting libraries. */
     schro_init();
 
     schro_debug_set_level(avccontext->debug);

     p_schro_params->decoder = schro_decoder_new();

     schro_decoder_set_skip_ratio(p_schro_params->decoder, 1);
 
     if (!p_schro_params->decoder)
         return -1;
 
     /* Initialize the decoded frame queue. */

     ff_dirac_schro_queue_init(&p_schro_params->dec_frame_queue);
     return 0;

 }
 

 static void libschroedinger_decode_buffer_free(SchroBuffer *schro_buf,
                                                void *priv)

 {
     av_freep(&priv);
 }
 

 static void libschroedinger_decode_frame_free(void *frame)

 {
     schro_frame_unref(frame);
 }
 
 static void libschroedinger_handle_first_access_unit(AVCodecContext *avccontext)
 {

     SchroDecoderParams *p_schro_params = avccontext->priv_data;

     SchroDecoder *decoder = p_schro_params->decoder;
 

     p_schro_params->format = schro_decoder_get_video_format(decoder);

     /* Tell FFmpeg about sequence details. */

     if (av_image_check_size(p_schro_params->format->width, p_schro_params->format->height,

                             0, avccontext) < 0) {

         av_log(avccontext, AV_LOG_ERROR, "invalid dimensions (%dx%d)\n",
                p_schro_params->format->width, p_schro_params->format->height);
         avccontext->height = avccontext->width = 0;

         return;

     }
     avccontext->height  = p_schro_params->format->height;
     avccontext->width   = p_schro_params->format->width;

     avccontext->pix_fmt = get_chroma_format(p_schro_params->format->chroma_format);

 
     if (ff_get_schro_frame_format(p_schro_params->format->chroma_format,
                                   &p_schro_params->frame_format) == -1) {
         av_log(avccontext, AV_LOG_ERROR,
                "This codec currently only supports planar YUV 4:2:0, 4:2:2 "
                "and 4:4:4 formats.\n");

         return;

     }
 
     avccontext->time_base.den = p_schro_params->format->frame_rate_numerator;
     avccontext->time_base.num = p_schro_params->format->frame_rate_denominator;
 

     if (!p_schro_params->dec_pic.data[0])

         avpicture_alloc(&p_schro_params->dec_pic,
                         avccontext->pix_fmt,
                         avccontext->width,
                         avccontext->height);
 }
 
 static int libschroedinger_decode_frame(AVCodecContext *avccontext,
                                         void *data, int *data_size,

                                         AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;

     SchroDecoderParams *p_schro_params = avccontext->priv_data;

     SchroDecoder *decoder = p_schro_params->decoder;
     AVPicture *picture = data;
     SchroBuffer *enc_buf;
     SchroFrame* frame;
     int state;
     int go = 1;

     int outer = 1;

     SchroParseUnitContext parse_ctx;

 
     *data_size = 0;
 

     SchroParseContextInit(&parse_ctx, buf, buf_size);

     if (!buf_size) {

         if (!p_schro_params->eos_signalled) {
             state = schro_decoder_push_end_of_stream(decoder);
             p_schro_params->eos_signalled = 1;
         }
     }
 

     /* Loop through all the individual parse units in the input buffer */
     do {

         if ((enc_buf = FindNextSchroParseUnit(&parse_ctx))) {

             /* Push buffer into decoder. */

             if (SCHRO_PARSE_CODE_IS_PICTURE(enc_buf->data[4]) &&
                 SCHRO_PARSE_CODE_NUM_REFS(enc_buf->data[4]) > 0)
                 avccontext->has_b_frames = 1;

             state = schro_decoder_push(decoder, enc_buf);

             if (state == SCHRO_DECODER_FIRST_ACCESS_UNIT)

                 libschroedinger_handle_first_access_unit(avccontext);

             go = 1;

         } else

             outer = 0;

 
         while (go) {
             /* Parse data and process result. */
             state = schro_decoder_wait(decoder);
             switch (state) {
             case SCHRO_DECODER_FIRST_ACCESS_UNIT:
                 libschroedinger_handle_first_access_unit(avccontext);
                 break;
 
             case SCHRO_DECODER_NEED_BITS:
                 /* Need more input data - stop iterating over what we have. */
                 go = 0;
                 break;
 
             case SCHRO_DECODER_NEED_FRAME:
                 /* Decoder needs a frame - create one and push it in. */

                 frame = ff_create_schro_frame(avccontext,
                                               p_schro_params->frame_format);

                 schro_decoder_add_output_picture(decoder, frame);
                 break;
 
             case SCHRO_DECODER_OK:
                 /* Pull a frame out of the decoder. */
                 frame = schro_decoder_pull(decoder);
 
                 if (frame)
                     ff_dirac_schro_queue_push_back(&p_schro_params->dec_frame_queue,
                                                    frame);
                 break;
             case SCHRO_DECODER_EOS:
                 go = 0;
                 p_schro_params->eos_pulled = 1;
                 schro_decoder_reset(decoder);
                 outer = 0;
                 break;
 
             case SCHRO_DECODER_ERROR:
                 return -1;
                 break;
             }

         }

     } while (outer);

 
     /* Grab next frame to be returned from the top of the queue. */
     frame = ff_dirac_schro_queue_pop(&p_schro_params->dec_frame_queue);
 

     if (frame) {

         memcpy(p_schro_params->dec_pic.data[0],
                frame->components[0].data,
                frame->components[0].length);

         memcpy(p_schro_params->dec_pic.data[1],
                frame->components[1].data,
                frame->components[1].length);

         memcpy(p_schro_params->dec_pic.data[2],
                frame->components[2].data,
                frame->components[2].length);

 
         /* Fill picture with current buffer data from Schroedinger. */
         avpicture_fill(picture, p_schro_params->dec_pic.data[0],
                        avccontext->pix_fmt,
                        avccontext->width, avccontext->height);
 
         *data_size = sizeof(AVPicture);
 
         /* Now free the frame resources. */

         libschroedinger_decode_frame_free(frame);

     }
     return buf_size;
 }
 
 

 static av_cold int libschroedinger_decode_close(AVCodecContext *avccontext)

 {

     SchroDecoderParams *p_schro_params = avccontext->priv_data;

     /* Free the decoder. */

     schro_decoder_free(p_schro_params->decoder);

     av_freep(&p_schro_params->format);
 

     avpicture_free(&p_schro_params->dec_pic);

 
     /* Free data in the output frame queue. */

     ff_dirac_schro_queue_free(&p_schro_params->dec_frame_queue,
                               libschroedinger_decode_frame_free);

     return 0;

 }
 

 static void libschroedinger_flush(AVCodecContext *avccontext)

 {
     /* Got a seek request. Free the decoded frames queue and then reset
      * the decoder */

     SchroDecoderParams *p_schro_params = avccontext->priv_data;

 
     /* Free data in the output frame queue. */

     ff_dirac_schro_queue_free(&p_schro_params->dec_frame_queue,
                               libschroedinger_decode_frame_free);

     ff_dirac_schro_queue_init(&p_schro_params->dec_frame_queue);

     schro_decoder_reset(p_schro_params->decoder);
     p_schro_params->eos_pulled = 0;
     p_schro_params->eos_signalled = 0;
 }
 

 AVCodec ff_libschroedinger_decoder = {

     .name           = "libschroedinger",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = CODEC_ID_DIRAC,

     .priv_data_size = sizeof(SchroDecoderParams),

     .init           = libschroedinger_decode_init,
     .close          = libschroedinger_decode_close,
     .decode         = libschroedinger_decode_frame,
     .capabilities   = CODEC_CAP_DELAY,

     .flush = libschroedinger_flush,

     .long_name = NULL_IF_CONFIG_SMALL("libschroedinger Dirac 2.2"),

 };