[FFmpeg-devel] [PATCH 4/6] lavc: APV decoder
Mark Thompson
sw at jkqxz.net
Sat Apr 19 22:07:02 EEST 2025
---
configure | 1 +
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/apv_decode.c | 327 +++++++++++++++++++++++++++++++++++++++
libavcodec/apv_decode.h | 80 ++++++++++
libavcodec/apv_dsp.c | 136 ++++++++++++++++
libavcodec/apv_dsp.h | 37 +++++
libavcodec/apv_entropy.c | 200 ++++++++++++++++++++++++
8 files changed, 783 insertions(+)
create mode 100644 libavcodec/apv_decode.c
create mode 100644 libavcodec/apv_decode.h
create mode 100644 libavcodec/apv_dsp.c
create mode 100644 libavcodec/apv_dsp.h
create mode 100644 libavcodec/apv_entropy.c
diff --git a/configure b/configure
index ca404d2797..ee270b770c 100755
--- a/configure
+++ b/configure
@@ -2935,6 +2935,7 @@ apng_decoder_select="inflate_wrapper"
apng_encoder_select="deflate_wrapper llvidencdsp"
aptx_encoder_select="audio_frame_queue"
aptx_hd_encoder_select="audio_frame_queue"
+apv_decoder_select="cbs_apv"
asv1_decoder_select="blockdsp bswapdsp idctdsp"
asv1_encoder_select="aandcttables bswapdsp fdctdsp pixblockdsp"
asv2_decoder_select="blockdsp bswapdsp idctdsp"
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index a5f5c4e904..e674671460 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -244,6 +244,7 @@ OBJS-$(CONFIG_APTX_HD_DECODER) += aptxdec.o aptx.o
OBJS-$(CONFIG_APTX_HD_ENCODER) += aptxenc.o aptx.o
OBJS-$(CONFIG_APNG_DECODER) += png.o pngdec.o pngdsp.o
OBJS-$(CONFIG_APNG_ENCODER) += png.o pngenc.o
+OBJS-$(CONFIG_APV_DECODER) += apv_decode.o apv_entropy.o apv_dsp.o
OBJS-$(CONFIG_ARBC_DECODER) += arbc.o
OBJS-$(CONFIG_ARGO_DECODER) += argo.o
OBJS-$(CONFIG_SSA_DECODER) += assdec.o ass.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index f10519617e..09f06c71d6 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -47,6 +47,7 @@ extern const FFCodec ff_anm_decoder;
extern const FFCodec ff_ansi_decoder;
extern const FFCodec ff_apng_encoder;
extern const FFCodec ff_apng_decoder;
+extern const FFCodec ff_apv_decoder;
extern const FFCodec ff_arbc_decoder;
extern const FFCodec ff_argo_decoder;
extern const FFCodec ff_asv1_encoder;
diff --git a/libavcodec/apv_decode.c b/libavcodec/apv_decode.c
new file mode 100644
index 0000000000..066b5a9735
--- /dev/null
+++ b/libavcodec/apv_decode.c
@@ -0,0 +1,327 @@
+/*
+ * 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
+ */
+
+#include "libavutil/mem_internal.h"
+
+#include "apv.h"
+#include "apv_decode.h"
+#include "apv_dsp.h"
+#include "avcodec.h"
+#include "cbs.h"
+#include "cbs_apv.h"
+#include "codec_internal.h"
+#include "decode.h"
+#include "thread.h"
+
+
+typedef struct APVDecodeContext {
+ CodedBitstreamContext *cbc;
+ APVDSPContext dsp;
+
+ CodedBitstreamFragment au;
+ APVDerivedTileInfo tile_info;
+
+ APVVLCLUT decode_lut;
+
+ AVFrame *output_frame;
+} APVDecodeContext;
+
+static const enum AVPixelFormat apv_format_table[5][5] = {
+ { AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16 },
+ { 0 }, // 4:2:0 is not valid.
+ { AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_YUV422P16 },
+ { AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV444P12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_YUV444P16 },
+ { AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA444P12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_YUVA444P16 },
+};
+
+static int apv_decode_check_format(AVCodecContext *avctx,
+ const APVRawFrameHeader *header)
+{
+ int err, bit_depth;
+
+ avctx->profile = header->frame_info.profile_idc;
+ avctx->level = header->frame_info.level_idc;
+
+ bit_depth = header->frame_info.bit_depth_minus8 + 8;
+ if (bit_depth < 8 || bit_depth > 16 || bit_depth % 2) {
+ avpriv_request_sample(avctx, "Bit depth %d", bit_depth);
+ return AVERROR_PATCHWELCOME;
+ }
+ avctx->pix_fmt =
+ apv_format_table[header->frame_info.chroma_format_idc][bit_depth - 4 >> 2];
+
+ err = ff_set_dimensions(avctx,
+ FFALIGN(header->frame_info.frame_width, 16),
+ FFALIGN(header->frame_info.frame_height, 16));
+ if (err < 0) {
+ // Unsupported frame size.
+ return err;
+ }
+ avctx->width = header->frame_info.frame_width;
+ avctx->height = header->frame_info.frame_height;
+
+ avctx->sample_aspect_ratio = (AVRational){ 1, 1 };
+
+ avctx->color_primaries = header->color_primaries;
+ avctx->color_trc = header->transfer_characteristics;
+ avctx->colorspace = header->matrix_coefficients;
+ avctx->color_range = header->full_range_flag ? AVCOL_RANGE_JPEG
+ : AVCOL_RANGE_MPEG;
+ avctx->chroma_sample_location = AVCHROMA_LOC_TOPLEFT;
+
+ avctx->refs = 0;
+ avctx->has_b_frames = 0;
+
+ return 0;
+}
+
+static av_cold int apv_decode_init(AVCodecContext *avctx)
+{
+ APVDecodeContext *apv = avctx->priv_data;
+ int err;
+
+ err = ff_cbs_init(&apv->cbc, AV_CODEC_ID_APV, avctx);
+ if (err < 0)
+ return err;
+
+ ff_apv_entropy_build_decode_lut(&apv->decode_lut);
+
+ ff_apv_dsp_init(&apv->dsp);
+
+ if (avctx->extradata) {
+ av_log(avctx, AV_LOG_WARNING,
+ "APV does not support extradata.\n");
+ }
+
+ return 0;
+}
+
+static av_cold int apv_decode_close(AVCodecContext *avctx)
+{
+ APVDecodeContext *apv = avctx->priv_data;
+
+ ff_cbs_fragment_free(&apv->au);
+ ff_cbs_close(&apv->cbc);
+
+ return 0;
+}
+
+static int apv_decode_block(AVCodecContext *avctx,
+ void *output,
+ ptrdiff_t pitch,
+ GetBitContext *gbc,
+ APVEntropyState *entropy_state,
+ int bit_depth,
+ int qp_shift,
+ const uint16_t *qmatrix)
+{
+ APVDecodeContext *apv = avctx->priv_data;
+ int err;
+
+ LOCAL_ALIGNED_32(int16_t, coeff, [64]);
+
+ err = ff_apv_entropy_decode_block(coeff, gbc, entropy_state);
+ if (err < 0)
+ return 0;
+
+ apv->dsp.decode_transquant(output, pitch,
+ coeff, qmatrix,
+ bit_depth, qp_shift);
+
+ return 0;
+}
+
+static int apv_decode_tile_component(AVCodecContext *avctx, void *data,
+ int job, int thread)
+{
+ APVRawFrame *input = data;
+ APVDecodeContext *apv = avctx->priv_data;
+ const CodedBitstreamAPVContext *apv_cbc = apv->cbc->priv_data;
+ const APVDerivedTileInfo *tile_info = &apv_cbc->tile_info;
+
+ int tile_index = job / apv_cbc->num_comp;
+ int comp_index = job % apv_cbc->num_comp;
+
+ int sub_w = comp_index == 0 ? 1 : apv_cbc->sub_width_c;
+ int sub_h = comp_index == 0 ? 1 : apv_cbc->sub_height_c;
+
+ APVRawTile *tile = &input->tile[tile_index];
+
+ int tile_y = tile_index / tile_info->tile_cols;
+ int tile_x = tile_index % tile_info->tile_cols;
+
+ int tile_start_x = tile_info->col_starts[tile_x];
+ int tile_start_y = tile_info->row_starts[tile_y];
+
+ int tile_width = tile_info->col_starts[tile_x + 1] - tile_start_x;
+ int tile_height = tile_info->row_starts[tile_y + 1] - tile_start_y;
+
+ int tile_mb_width = tile_width / APV_MB_WIDTH;
+ int tile_mb_height = tile_height / APV_MB_HEIGHT;
+
+ int blk_mb_width = 2 / sub_w;
+ int blk_mb_height = 2 / sub_h;
+
+ int bit_depth;
+ int qp_shift;
+ LOCAL_ALIGNED_32(uint16_t, qmatrix_scaled, [64]);
+
+ GetBitContext gbc;
+
+ APVEntropyState entropy_state = {
+ .log_ctx = avctx,
+ .decode_lut = &apv->decode_lut,
+ .prev_dc = 0,
+ .prev_dc_diff = 20,
+ .prev_1st_ac_level = 0,
+ };
+
+ init_get_bits8(&gbc, tile->tile_data[comp_index],
+ tile->tile_header.tile_data_size[comp_index]);
+
+ // Combine the bitstream quantisation matrix with the qp scaling
+ // in advance. (Including qp_shift as well would overflow 16 bits.)
+ // Fix the row ordering at the same time.
+ {
+ static const uint8_t apv_level_scale[6] = { 40, 45, 51, 57, 64, 71 };
+ int qp = tile->tile_header.tile_qp[comp_index];
+ int level_scale = apv_level_scale[qp % 6];
+
+ bit_depth = apv_cbc->bit_depth;
+ qp_shift = qp / 6;
+
+ for (int y = 0; y < 8; y++) {
+ for (int x = 0; x < 8; x++)
+ qmatrix_scaled[y * 8 + x] = level_scale *
+ input->frame_header.quantization_matrix.q_matrix[comp_index][x][y];
+ }
+ }
+
+ for (int mb_y = 0; mb_y < tile_mb_height; mb_y++) {
+ for (int mb_x = 0; mb_x < tile_mb_width; mb_x++) {
+ for (int blk_y = 0; blk_y < blk_mb_height; blk_y++) {
+ for (int blk_x = 0; blk_x < blk_mb_width; blk_x++) {
+ int frame_y = (tile_start_y +
+ APV_MB_HEIGHT * mb_y +
+ APV_TR_SIZE * blk_y) / sub_h;
+ int frame_x = (tile_start_x +
+ APV_MB_WIDTH * mb_x +
+ APV_TR_SIZE * blk_x) / sub_w;
+
+ ptrdiff_t frame_pitch = apv->output_frame->linesize[comp_index];
+ uint8_t *block_start = apv->output_frame->data[comp_index] +
+ frame_y * frame_pitch + 2 * frame_x;
+
+ apv_decode_block(avctx,
+ block_start, frame_pitch,
+ &gbc, &entropy_state,
+ bit_depth,
+ qp_shift,
+ qmatrix_scaled);
+ }
+ }
+ }
+ }
+
+ av_log(avctx, AV_LOG_DEBUG,
+ "Decoded tile %d component %d: %dx%d MBs starting at (%d,%d)\n",
+ tile_index, comp_index, tile_mb_width, tile_mb_height,
+ tile_start_x, tile_start_y);
+
+ return 0;
+}
+
+static int apv_decode(AVCodecContext *avctx, AVFrame *output,
+ APVRawFrame *input)
+{
+ APVDecodeContext *apv = avctx->priv_data;
+ const CodedBitstreamAPVContext *apv_cbc = apv->cbc->priv_data;
+ const APVDerivedTileInfo *tile_info = &apv_cbc->tile_info;
+ int err, job_count;
+
+ err = apv_decode_check_format(avctx, &input->frame_header);
+ if (err < 0) {
+ av_log(avctx, AV_LOG_ERROR, "Unsupported format parameters.\n");
+ return err;
+ }
+
+ err = ff_thread_get_buffer(avctx, output, 0);
+ if (err) {
+ av_log(avctx, AV_LOG_ERROR, "No output frame supplied.\n");
+ return err;
+ }
+
+ apv->output_frame = output;
+
+ // Each component within a tile is independent of every other,
+ // so we can decode all in parallel.
+ job_count = tile_info->num_tiles * apv_cbc->num_comp;
+
+ avctx->execute2(avctx, apv_decode_tile_component,
+ input, NULL, job_count);
+
+ return 0;
+}
+
+static int apv_decode_frame(AVCodecContext *avctx, AVFrame *frame,
+ int *got_frame, AVPacket *packet)
+{
+ APVDecodeContext *apv = avctx->priv_data;
+ CodedBitstreamFragment *au = &apv->au;
+ int err;
+
+ err = ff_cbs_read_packet(apv->cbc, au, packet);
+ if (err < 0) {
+ av_log(avctx, AV_LOG_ERROR, "Failed to read packet.\n");
+ return err;
+ }
+
+ for (int i = 0; i < au->nb_units; i++) {
+ CodedBitstreamUnit *pbu = &au->units[i];
+
+ switch (pbu->type) {
+ case APV_PBU_PRIMARY_FRAME:
+ err = apv_decode(avctx, frame, pbu->content);
+ if (err < 0)
+ return err;
+ *got_frame = 1;
+ break;
+ default:
+ av_log(avctx, AV_LOG_WARNING,
+ "Ignoring unsupported PBU type %d.\n", pbu->type);
+ }
+ }
+
+ ff_cbs_fragment_reset(au);
+
+ return packet->size;
+}
+
+const FFCodec ff_apv_decoder = {
+ .p.name = "apv",
+ CODEC_LONG_NAME("Advanced Professional Video"),
+ .p.type = AVMEDIA_TYPE_VIDEO,
+ .p.id = AV_CODEC_ID_APV,
+ .priv_data_size = sizeof(APVDecodeContext),
+ .init = apv_decode_init,
+ .close = apv_decode_close,
+ FF_CODEC_DECODE_CB(apv_decode_frame),
+ .p.capabilities = AV_CODEC_CAP_DR1 |
+ AV_CODEC_CAP_SLICE_THREADS |
+ AV_CODEC_CAP_FRAME_THREADS,
+};
diff --git a/libavcodec/apv_decode.h b/libavcodec/apv_decode.h
new file mode 100644
index 0000000000..34c6176ea0
--- /dev/null
+++ b/libavcodec/apv_decode.h
@@ -0,0 +1,80 @@
+/*
+ * 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
+ */
+
+#ifndef AVCODEC_APV_DECODE_H
+#define AVCODEC_APV_DECODE_H
+
+#include <stdint.h>
+
+#include "apv.h"
+#include "avcodec.h"
+#include "get_bits.h"
+
+
+// Number of bits in the entropy look-up tables.
+// It may be desirable to tune this per-architecture, as a larger LUT
+// trades greater memory use for fewer instructions.
+// (N bits -> 24*2^N bytes of tables; 9 -> 12KB of tables.)
+#define APV_VLC_LUT_BITS 9
+#define APV_VLC_LUT_SIZE (1 << APV_VLC_LUT_BITS)
+
+typedef struct APVVLCLUTEntry {
+ uint16_t result; // Return value if not reading more.
+ uint8_t consume; // Number of bits to consume.
+ uint8_t more; // Whether to read additional bits.
+} APVVLCLUTEntry;
+
+typedef struct APVVLCLUT {
+ APVVLCLUTEntry lut[6][APV_VLC_LUT_SIZE];
+} APVVLCLUT;
+
+typedef struct APVEntropyState {
+ void *log_ctx;
+
+ const APVVLCLUT *decode_lut;
+
+ int16_t prev_dc;
+ int16_t prev_dc_diff;
+ int16_t prev_1st_ac_level;
+} APVEntropyState;
+
+
+/**
+ * Build the decoder VLC look-up table.
+ */
+void ff_apv_entropy_build_decode_lut(APVVLCLUT *decode_lut);
+
+/**
+ * Entropy decode a single 8x8 block to coefficients.
+ *
+ * Outputs in block order (dezigzag already applied).
+ */
+int ff_apv_entropy_decode_block(int16_t *coeff,
+ GetBitContext *gbc,
+ APVEntropyState *state);
+
+/**
+ * Read a single APV VLC code.
+ *
+ * This entrypoint is exposed for testing.
+ */
+unsigned int ff_apv_read_vlc(GetBitContext *gbc, int k_param,
+ const APVVLCLUT *lut);
+
+
+#endif /* AVCODEC_APV_DECODE_H */
diff --git a/libavcodec/apv_dsp.c b/libavcodec/apv_dsp.c
new file mode 100644
index 0000000000..6b8b6ce590
--- /dev/null
+++ b/libavcodec/apv_dsp.c
@@ -0,0 +1,136 @@
+/*
+ * 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
+ */
+
+#include <stdint.h>
+
+#include "config.h"
+#include "libavutil/attributes.h"
+#include "libavutil/common.h"
+
+#include "apv.h"
+#include "apv_dsp.h"
+
+
+static const int8_t apv_trans_matrix[8][8] = {
+ { 64, 64, 64, 64, 64, 64, 64, 64 },
+ { 89, 75, 50, 18, -18, -50, -75, -89 },
+ { 84, 35, -35, -84, -84, -35, 35, 84 },
+ { 75, -18, -89, -50, 50, 89, 18, -75 },
+ { 64, -64, -64, 64, 64, -64, -64, 64 },
+ { 50, -89, 18, 75, -75, -18, 89, -50 },
+ { 35, -84, 84, -35, -35, 84, -84, 35 },
+ { 18, -50, 75, -89, 89, -75, 50, -18 },
+};
+
+static void apv_decode_transquant_c(void *output,
+ ptrdiff_t pitch,
+ const int16_t *input_flat,
+ const int16_t *qmatrix_flat,
+ int64_t bit_depth,
+ int64_t qp_shift)
+{
+ const int16_t (*input)[8] = (const int16_t(*)[8])input_flat;
+ const int16_t (*qmatrix)[8] = (const int16_t(*)[8])qmatrix_flat;
+
+ int16_t scaled_coeff[8][8];
+ int32_t recon_sample[8][8];
+
+ // Dequant.
+ {
+ // Note that level_scale was already combined into qmatrix
+ // before we got here.
+ int bd_shift = bit_depth + 3 - 5;
+
+ for (int y = 0; y < 8; y++) {
+ for (int x = 0; x < 8; x++) {
+ int coeff = (((input[y][x] * qmatrix[y][x]) << qp_shift) +
+ (1 << (bd_shift - 1))) >> bd_shift;
+
+ scaled_coeff[y][x] =
+ av_clip(coeff, APV_MIN_TRANS_COEFF,
+ APV_MAX_TRANS_COEFF);
+ }
+ }
+ }
+
+ // Transform.
+ {
+ int32_t tmp[8][8];
+
+ // Vertical transform of columns.
+ for (int x = 0; x < 8; x++) {
+ for (int i = 0; i < 8; i++) {
+ int sum = 0;
+ for (int j = 0; j < 8; j++)
+ sum += apv_trans_matrix[j][i] * scaled_coeff[j][x];
+ tmp[i][x] = sum;
+ }
+ }
+
+ // Renormalise.
+ for (int x = 0; x < 8; x++) {
+ for (int y = 0; y < 8; y++)
+ tmp[y][x] = (tmp[y][x] + 64) >> 7;
+ }
+
+ // Horizontal transform of rows.
+ for (int y = 0; y < 8; y++) {
+ for (int i = 0; i < 8; i++) {
+ int sum = 0;
+ for (int j = 0; j < 8; j++)
+ sum += apv_trans_matrix[j][i] * tmp[y][j];
+ recon_sample[y][i] = sum;
+ }
+ }
+ }
+
+ // Output.
+ if (bit_depth == 8) {
+ uint8_t *ptr = output;
+ int bd_shift = 20 - bit_depth;
+
+ for (int y = 0; y < 8; y++) {
+ for (int x = 0; x < 8; x++) {
+ int sample = ((recon_sample[y][x] +
+ (1 << (bd_shift - 1))) >> bd_shift) +
+ (1 << (bit_depth - 1));
+ ptr[x] = av_clip_uintp2(sample, bit_depth);
+ }
+ ptr += pitch;
+ }
+ } else {
+ uint16_t *ptr = output;
+ int bd_shift = 20 - bit_depth;
+ pitch /= 2; // Pitch was in bytes, 2 bytes per sample.
+
+ for (int y = 0; y < 8; y++) {
+ for (int x = 0; x < 8; x++) {
+ int sample = ((recon_sample[y][x] +
+ (1 << (bd_shift - 1))) >> bd_shift) +
+ (1 << (bit_depth - 1));
+ ptr[x] = av_clip_uintp2(sample, bit_depth);
+ }
+ ptr += pitch;
+ }
+ }
+}
+
+av_cold void ff_apv_dsp_init(APVDSPContext *dsp)
+{
+ dsp->decode_transquant = apv_decode_transquant_c;
+}
diff --git a/libavcodec/apv_dsp.h b/libavcodec/apv_dsp.h
new file mode 100644
index 0000000000..13f401c4cc
--- /dev/null
+++ b/libavcodec/apv_dsp.h
@@ -0,0 +1,37 @@
+/*
+ * 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
+ */
+
+#ifndef AVCODEC_APV_DSP_H
+#define AVCODEC_APV_DSP_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+
+typedef struct APVDSPContext {
+ void (*decode_transquant)(void *output,
+ ptrdiff_t pitch,
+ const int16_t *input,
+ const int16_t *qmatrix,
+ int64_t bit_depth,
+ int64_t qp_shift);
+} APVDSPContext;
+
+void ff_apv_dsp_init(APVDSPContext *dsp);
+
+#endif /* AVCODEC_APV_DSP_H */
diff --git a/libavcodec/apv_entropy.c b/libavcodec/apv_entropy.c
new file mode 100644
index 0000000000..00e0b4fbdf
--- /dev/null
+++ b/libavcodec/apv_entropy.c
@@ -0,0 +1,200 @@
+/*
+ * 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
+ */
+
+#include "apv.h"
+#include "apv_decode.h"
+
+
+void ff_apv_entropy_build_decode_lut(APVVLCLUT *decode_lut)
+{
+ const int code_len = APV_VLC_LUT_BITS;
+ const int lut_size = APV_VLC_LUT_SIZE;
+
+ for (int k = 0; k <= 5; k++) {
+ for (unsigned int code = 0; code < lut_size; code++) {
+ APVVLCLUTEntry *ent = &decode_lut->lut[k][code];
+ unsigned int first_bit = code & (1 << code_len - 1);
+ unsigned int remaining_bits = code ^ first_bit;
+
+ if (first_bit) {
+ ent->consume = 1 + k;
+ ent->result = remaining_bits >> (code_len - k - 1);
+ ent->more = 0;
+ } else {
+ unsigned int second_bit = code & (1 << code_len - 2);
+ remaining_bits ^= second_bit;
+
+ if (second_bit) {
+ unsigned int bits_left = code_len - 2;
+ unsigned int first_set = bits_left - av_log2(remaining_bits);
+ unsigned int last_bits = first_set - 1 + k;
+
+ if (first_set + last_bits <= bits_left) {
+ // Whole code fits here.
+ ent->consume = 2 + first_set + last_bits;
+ ent->result = ((2 << k) +
+ (((1 << first_set - 1) - 1) << k) +
+ ((code >> bits_left - first_set - last_bits) & (1 << last_bits) - 1));
+ ent->more = 0;
+ } else {
+ // Need to read more, collapse to default.
+ ent->consume = 2;
+ ent->more = 1;
+ }
+ } else {
+ ent->consume = 2 + k;
+ ent->result = (1 << k) + (remaining_bits >> (code_len - k - 2));
+ ent->more = 0;
+ }
+ }
+ }
+ }
+}
+
+av_always_inline
+static unsigned int apv_read_vlc(GetBitContext *gbc, int k_param,
+ const APVVLCLUT *lut)
+{
+ unsigned int next_bits;
+ const APVVLCLUTEntry *ent;
+
+ next_bits = show_bits(gbc, APV_VLC_LUT_BITS);
+ ent = &lut->lut[k_param][next_bits];
+
+ if (ent->more) {
+ unsigned int leading_zeroes;
+
+ skip_bits(gbc, ent->consume);
+
+ next_bits = show_bits(gbc, 16);
+ leading_zeroes = 15 - av_log2(next_bits);
+
+ skip_bits(gbc, leading_zeroes + 1);
+
+ return (2 << k_param) +
+ ((1 << leading_zeroes) - 1) * (1 << k_param) +
+ get_bits(gbc, leading_zeroes + k_param);
+ } else {
+ skip_bits(gbc, ent->consume);
+ return ent->result;
+ }
+}
+
+unsigned int ff_apv_read_vlc(GetBitContext *gbc, int k_param,
+ const APVVLCLUT *lut)
+{
+ return apv_read_vlc(gbc, k_param, lut);
+}
+
+int ff_apv_entropy_decode_block(int16_t *coeff,
+ GetBitContext *gbc,
+ APVEntropyState *state)
+{
+ const APVVLCLUT *lut = state->decode_lut;
+ int k_param;
+
+ // DC coefficient.
+ {
+ int abs_dc_coeff_diff;
+ int sign_dc_coeff_diff;
+ int dc_coeff;
+
+ k_param = av_clip(state->prev_dc_diff >> 1, 0, 5);
+ abs_dc_coeff_diff = apv_read_vlc(gbc, k_param, lut);
+
+ if (abs_dc_coeff_diff > 0)
+ sign_dc_coeff_diff = get_bits1(gbc);
+ else
+ sign_dc_coeff_diff = 0;
+
+ if (sign_dc_coeff_diff)
+ dc_coeff = state->prev_dc - abs_dc_coeff_diff;
+ else
+ dc_coeff = state->prev_dc + abs_dc_coeff_diff;
+
+ if (dc_coeff < APV_MIN_TRANS_COEFF ||
+ dc_coeff > APV_MAX_TRANS_COEFF) {
+ av_log(state->log_ctx, AV_LOG_ERROR,
+ "Out-of-range DC coefficient value: %d "
+ "(from prev_dc %d abs_dc_coeff_diff %d sign_dc_coeff_diff %d)\n",
+ dc_coeff, state->prev_dc, abs_dc_coeff_diff, sign_dc_coeff_diff);
+ return AVERROR_INVALIDDATA;
+ }
+
+ coeff[0] = dc_coeff;
+
+ state->prev_dc = dc_coeff;
+ state->prev_dc_diff = abs_dc_coeff_diff;
+ }
+
+ // AC coefficients.
+ {
+ int scan_pos = 1;
+ int first_ac = 1;
+ int prev_level = state->prev_1st_ac_level;
+ int prev_run = 0;
+
+ do {
+ int coeff_zero_run;
+
+ k_param = av_clip(prev_run >> 2, 0, 2);
+ coeff_zero_run = apv_read_vlc(gbc, k_param, lut);
+
+ if (coeff_zero_run > APV_BLK_COEFFS - scan_pos) {
+ av_log(state->log_ctx, AV_LOG_ERROR,
+ "Out-of-range zero-run value: %d (at scan pos %d)\n",
+ coeff_zero_run, scan_pos);
+ return AVERROR_INVALIDDATA;
+ }
+
+ for (int i = 0; i < coeff_zero_run; i++) {
+ coeff[ff_zigzag_direct[scan_pos]] = 0;
+ ++scan_pos;
+ }
+ prev_run = coeff_zero_run;
+
+ if (scan_pos < APV_BLK_COEFFS) {
+ int abs_ac_coeff_minus1;
+ int sign_ac_coeff;
+ int level;
+
+ k_param = av_clip(prev_level >> 2, 0, 4);
+ abs_ac_coeff_minus1 = apv_read_vlc(gbc, k_param, lut);
+ sign_ac_coeff = get_bits(gbc, 1);
+
+ if (sign_ac_coeff)
+ level = -abs_ac_coeff_minus1 - 1;
+ else
+ level = abs_ac_coeff_minus1 + 1;
+
+ coeff[ff_zigzag_direct[scan_pos]] = level;
+
+ prev_level = abs_ac_coeff_minus1 + 1;
+ if (first_ac) {
+ state->prev_1st_ac_level = prev_level;
+ first_ac = 0;
+ }
+
+ ++scan_pos;
+ }
+
+ } while (scan_pos < APV_BLK_COEFFS);
+ }
+
+ return 0;
+}
--
2.47.2
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