static av_always_inline void dnxhd_encode_dc(DNXHDEncContext *ctx, int diff) { int nbits; if (diff < 0) { nbits = av_log2_16bit(-2*diff); diff--; } else { nbits = av_log2_16bit(2*diff); } put_bits(&ctx->m.pb, ctx->cid_table->dc_bits[nbits] + nbits, (ctx->cid_table->dc_codes[nbits]<<nbits) + (diff & ((1 << nbits) - 1))); }
/** * \param s pointer to MpegEncContext structure * \param block pointer to the DCT block to emit * \param n * * This routine is a duplicate of encode_block in mjpeg.c */ static void encode_block(MpegEncContext *s, int16_t *block, int n) { int mant, nbits, code, i, j; int component, dc, run, last_index, val; MJpegContext *m = s->mjpeg_ctx; uint8_t *huff_size_ac; uint16_t *huff_code_ac; /* DC coef */ component = (n <= 3 ? 0 : n - 4 + 1); dc = block[0]; /* overflow is impossible */ val = dc - s->last_dc[component]; if (n < 4) { encode_dc(s, val, m->huff_size_dc_luminance, m->huff_code_dc_luminance); huff_size_ac = m->huff_size_ac_luminance; huff_code_ac = m->huff_code_ac_luminance; } else { encode_dc(s, val, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance); huff_size_ac = m->huff_size_ac_chrominance; huff_code_ac = m->huff_code_ac_chrominance; } s->last_dc[component] = dc; /* AC coefs */ run = 0; last_index = s->block_last_index[n]; for (i = 1; i <= last_index; i++) { j = s->intra_scantable.permutated[i]; val = block[j]; if (val == 0) run++; else { while (run >= 16) { put_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]); run -= 16; } mant = val; if (val < 0) { val = -val; mant--; } nbits= av_log2_16bit(val) + 1; code = (run << 4) | nbits; put_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]); put_bits(&s->pb, nbits, mant & ((1 << nbits) - 1)); run = 0; } } /* output EOB only if not already 64 values */ if (last_index < 63 || run != 0) put_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]); }
/** * This routine is only intended to be used from encode_block * * \param s pointer to MpegEncContext structure * \param val the DC value to emit * \param huff_size pointer to huffman code size array * \param huff_code pointer to the code array corresponding to \a huff_size * * This routine is a clone of mjpeg_encode_dc */ static inline void encode_dc(MpegEncContext *s, int val, uint8_t *huff_size, uint16_t *huff_code) { int mant, nbits; if (val == 0) { put_bits(&s->pb, huff_size[0], huff_code[0]); } else { mant = val; if (val < 0) { val = -val; mant--; } nbits= av_log2_16bit(val) + 1; put_bits(&s->pb, huff_size[nbits], huff_code[nbits]); put_bits(&s->pb, nbits, mant & ((1 << nbits) - 1)); } }