You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

138 lines
3.9KB

  1. /*
  2. * Aura 2 decoder
  3. *
  4. * This file is part of FFmpeg.
  5. *
  6. * FFmpeg is free software; you can redistribute it and/or
  7. * modify it under the terms of the GNU Lesser General Public
  8. * License as published by the Free Software Foundation; either
  9. * version 2.1 of the License, or (at your option) any later version.
  10. *
  11. * FFmpeg is distributed in the hope that it will be useful,
  12. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14. * Lesser General Public License for more details.
  15. *
  16. * You should have received a copy of the GNU Lesser General Public
  17. * License along with FFmpeg; if not, write to the Free Software
  18. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19. */
  20. /**
  21. * @file
  22. * Aura 2 decoder
  23. */
  24. #include "avcodec.h"
  25. typedef struct AuraDecodeContext {
  26. AVCodecContext *avctx;
  27. AVFrame frame;
  28. } AuraDecodeContext;
  29. static av_cold int aura_decode_init(AVCodecContext *avctx)
  30. {
  31. AuraDecodeContext *s = avctx->priv_data;
  32. s->avctx = avctx;
  33. /* width needs to be divisible by 4 for this codec to work */
  34. if (avctx->width & 0x3)
  35. return -1;
  36. avctx->pix_fmt = PIX_FMT_YUV422P;
  37. avcodec_get_frame_defaults(&s->frame);
  38. return 0;
  39. }
  40. static int aura_decode_frame(AVCodecContext *avctx,
  41. void *data, int *data_size,
  42. AVPacket *pkt)
  43. {
  44. AuraDecodeContext *s=avctx->priv_data;
  45. uint8_t *Y, *U, *V;
  46. uint8_t val;
  47. int x, y;
  48. const uint8_t *buf = pkt->data;
  49. /* prediction error tables (make it clear that they are signed values) */
  50. const int8_t *delta_table = (const int8_t*)buf + 16;
  51. if (pkt->size != 48 + avctx->height * avctx->width) {
  52. av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
  53. pkt->size, 48 + avctx->height * avctx->width);
  54. return -1;
  55. }
  56. /* pixel data starts 48 bytes in, after 3x16-byte tables */
  57. buf += 48;
  58. if(s->frame.data[0])
  59. avctx->release_buffer(avctx, &s->frame);
  60. s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
  61. s->frame.reference = 0;
  62. if(avctx->get_buffer(avctx, &s->frame) < 0) {
  63. av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  64. return -1;
  65. }
  66. Y = s->frame.data[0];
  67. U = s->frame.data[1];
  68. V = s->frame.data[2];
  69. /* iterate through each line in the height */
  70. for (y = 0; y < avctx->height; y++) {
  71. /* reset predictors */
  72. val = *buf++;
  73. U[0] = val & 0xF0;
  74. Y[0] = val << 4;
  75. val = *buf++;
  76. V[0] = val & 0xF0;
  77. Y[1] = Y[0] + delta_table[val & 0xF];
  78. Y += 2; U++; V++;
  79. /* iterate through the remaining pixel groups (4 pixels/group) */
  80. for (x = 1; x < (avctx->width >> 1); x++) {
  81. val = *buf++;
  82. U[0] = U[-1] + delta_table[val >> 4];
  83. Y[0] = Y[-1] + delta_table[val & 0xF];
  84. val = *buf++;
  85. V[0] = V[-1] + delta_table[val >> 4];
  86. Y[1] = Y[ 0] + delta_table[val & 0xF];
  87. Y += 2; U++; V++;
  88. }
  89. Y += s->frame.linesize[0] - avctx->width;
  90. U += s->frame.linesize[1] - (avctx->width >> 1);
  91. V += s->frame.linesize[2] - (avctx->width >> 1);
  92. }
  93. *data_size=sizeof(AVFrame);
  94. *(AVFrame*)data= s->frame;
  95. return pkt->size;
  96. }
  97. static av_cold int aura_decode_end(AVCodecContext *avctx)
  98. {
  99. AuraDecodeContext *s = avctx->priv_data;
  100. if (s->frame.data[0])
  101. avctx->release_buffer(avctx, &s->frame);
  102. return 0;
  103. }
  104. AVCodec ff_aura2_decoder = {
  105. .name = "aura2",
  106. .type = AVMEDIA_TYPE_VIDEO,
  107. .id = CODEC_ID_AURA2,
  108. .priv_data_size = sizeof(AuraDecodeContext),
  109. .init = aura_decode_init,
  110. .close = aura_decode_end,
  111. .decode = aura_decode_frame,
  112. .capabilities = CODEC_CAP_DR1,
  113. .long_name = NULL_IF_CONFIG_SMALL("Auravision Aura 2"),
  114. };