On 1/22/2019 11:54 AM, Paul B Mahol wrote:
> On 1/22/19, James Almer <jamr...@gmail.com> wrote:
>> On 1/22/2019 10:30 AM, Paul B Mahol wrote:
>>> On 1/22/19, James Almer <jamr...@gmail.com> wrote:
>>>> On 1/22/2019 6:55 AM, Paul B Mahol wrote:
>>>>> Thanks Kostya for great help in reversing binary.
>>>>>
>>>>> Signed-off-by: Paul B Mahol <one...@gmail.com>
>>>>> ---
>>>>> libavcodec/Makefile | 1 +
>>>>> libavcodec/allcodecs.c | 1 +
>>>>> libavcodec/arbc.c | 203 ++++++++++++++++++++++++++++++++++++++++
>>>>> libavcodec/avcodec.h | 1 +
>>>>> libavcodec/codec_desc.c | 7 ++
>>>>> libavformat/riff.c | 1 +
>>>>> 6 files changed, 214 insertions(+)
>>>>> create mode 100644 libavcodec/arbc.c
>>>>>
>>>>> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
>>>>> index bf746c143d..8e240aecf0 100644
>>>>> --- a/libavcodec/Makefile
>>>>> +++ b/libavcodec/Makefile
>>>>> @@ -198,6 +198,7 @@ OBJS-$(CONFIG_APTX_HD_DECODER) += aptx.o
>>>>> OBJS-$(CONFIG_APTX_HD_ENCODER) += aptx.o
>>>>> OBJS-$(CONFIG_APNG_DECODER) += png.o pngdec.o pngdsp.o
>>>>> OBJS-$(CONFIG_APNG_ENCODER) += png.o pngenc.o
>>>>> +OBJS-$(CONFIG_ARBC_DECODER) += arbc.o
>>>>> OBJS-$(CONFIG_SSA_DECODER) += assdec.o ass.o
>>>>> OBJS-$(CONFIG_SSA_ENCODER) += assenc.o ass.o
>>>>> OBJS-$(CONFIG_ASS_DECODER) += assdec.o ass.o
>>>>> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
>>>>> index fe0376e27e..5cbb09a5a4 100644
>>>>> --- a/libavcodec/allcodecs.c
>>>>> +++ b/libavcodec/allcodecs.c
>>>>> @@ -41,6 +41,7 @@ extern AVCodec ff_anm_decoder;
>>>>> extern AVCodec ff_ansi_decoder;
>>>>> extern AVCodec ff_apng_encoder;
>>>>> extern AVCodec ff_apng_decoder;
>>>>> +extern AVCodec ff_arbc_decoder;
>>>>> extern AVCodec ff_asv1_encoder;
>>>>> extern AVCodec ff_asv1_decoder;
>>>>> extern AVCodec ff_asv2_encoder;
>>>>> diff --git a/libavcodec/arbc.c b/libavcodec/arbc.c
>>>>> new file mode 100644
>>>>> index 0000000000..59a1d7bf0a
>>>>> --- /dev/null
>>>>> +++ b/libavcodec/arbc.c
>>>>> @@ -0,0 +1,203 @@
>>>>> +/*
>>>>> + * Gryphon's Anim Compressor decoder
>>>>> + * Copyright (c) 2018 Paul B Mahol
>>>>> + *
>>>>> + * 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 <stdio.h>
>>>>> +#include <stdlib.h>
>>>>> +#include <string.h>
>>>>> +
>>>>> +#include "libavutil/imgutils.h"
>>>>> +#include "libavutil/internal.h"
>>>>> +#include "libavutil/intreadwrite.h"
>>>>> +#include "libavutil/mem.h"
>>>>> +
>>>>> +#include "avcodec.h"
>>>>> +#include "bytestream.h"
>>>>> +#include "internal.h"
>>>>> +
>>>>> +typedef struct ARBCContext {
>>>>> + GetByteContext gb;
>>>>> +
>>>>> + AVFrame *prev_frame;
>>>>> +} ARBCContext;
>>>>> +
>>>>> +static void fill_tile4(AVCodecContext *avctx, uint8_t *color, AVFrame
>>>>> *frame)
>>>>> +{
>>>>> + ARBCContext *s = avctx->priv_data;
>>>>> + GetByteContext *gb = &s->gb;
>>>>> + int nb_tiles = bytestream2_get_le16(gb);
>>>>> + int h = avctx->height - 1;
>>>>> +
>>>>> + for (int i = 0; i < nb_tiles; i++) {
>>>>> + int y = bytestream2_get_byte(gb);
>>>>> + int x = bytestream2_get_byte(gb);
>>>>> + uint16_t mask = bytestream2_get_le16(gb);
>>>>> + int start_y = y * 4, start_x = x * 4;
>>>>> + int end_y = start_y + 4, end_x = start_x + 4;
>>>>> +
>>>>> + for (int j = start_y; j < end_y; j++) {
>>>>> + for (int k = start_x; k < end_x; k++) {
>>>>> + if (mask & 0x8000) {
>>>>> + if (j >= avctx->height || k >= avctx->width)
>>>>> + continue;
>>>>> + frame->data[0][frame->linesize[0] * (h - j) + 3 * k
>>>>> +
>>>>> 0] = color[0];
>>>>> + frame->data[0][frame->linesize[0] * (h - j) + 3 * k
>>>>> +
>>>>> 1] = color[1];
>>>>> + frame->data[0][frame->linesize[0] * (h - j) + 3 * k
>>>>> +
>>>>> 2] = color[2];
>>>>> + }
>>>>> + mask = mask << 1;
>>>>
>>>> get_bits(). Same below.
>>>
>>> Oh, come one, I had enough of this nonsense.
>>> This is 16 bit number, using fucking get bits is overkill.
>>> Get over it.
>>
>> Don't get pissy about nothing. I asked nothing that deserves that kind
>> of reaction.
>>
>> Doing mask & 0x8000 then shifting it left by one at every loop is weird
>> and one of the reasons why get_bits was written for. But do however you
>> prefer.
>
> Correct me if I'm wrong, but I can not use get_bits here for all data
> (something its read little endian sometimes it picks bits from top),
You're right, nb_tiles and nb_segments and this loop probably can't use
the same get_bits context.
> and using it only for
> single 16bit number is silly.
>
>>
>>>
>>>>
>>>>> + }
>>>>> + }
>>>>> + }
>>>>> +}
>>>>> +
>>>>> +static void fill_tileX(AVCodecContext *avctx, int tile_width, int
>>>>> tile_height,
>>>>> + uint8_t *color, AVFrame *frame)
>>>>> +{
>>>>> + ARBCContext *s = avctx->priv_data;
>>>>> + GetByteContext *gb = &s->gb;
>>>>> + const int step_h = tile_height / 4;
>>>>> + const int step_w = tile_width / 4;
>>>>> + int nb_tiles = bytestream2_get_le16(gb);
>>>>> + int h = avctx->height - 1;
>>>>> +
>>>>> + for (int i = 0; i < nb_tiles; i++) {
>>>>> + int y = bytestream2_get_byte(gb);
>>>>> + int x = bytestream2_get_byte(gb);
>>>>> + uint16_t mask = bytestream2_get_le16(gb);
>>>>> + int start_y = y * tile_height, start_x = x * tile_width;
>>>>> + int end_y = start_y + tile_height, end_x = start_x +
>>>>> tile_width;
>>>>> +
>>>>> + for (int j = start_y; j < end_y; j += step_h) {
>>>>> + for (int k = start_x; k < end_x; k += step_w) {
>>>>> + if (mask & 0x8000U) {
>>>>> + for (int m = 0; m < step_h; m++) {
>>>>> + for (int n = 0; n < step_w; n++) {
>>>>> + if (j + m >= avctx->height || k + n >=
>>>>> avctx->width)
>>>>> + continue;
>>>>> + frame->data[0][frame->linesize[0] * (h - (j
>>>>> +
>>>>> m)) + 3 * (k + n) + 0] = color[0];
>>>>> + frame->data[0][frame->linesize[0] * (h - (j
>>>>> +
>>>>> m)) + 3 * (k + n) + 1] = color[1];
>>>>> + frame->data[0][frame->linesize[0] * (h - (j
>>>>> +
>>>>> m)) + 3 * (k + n) + 2] = color[2];
>>>>> + }
>>>>> + }
>>>>> + }
>>>>> + mask = mask << 1;
>>>>> + }
>>>>> + }
>>>>> + }
>>>>> +}
>>>>> +
>>>>> +static int decode_frame(AVCodecContext *avctx, void *data,
>>>>> + int *got_frame, AVPacket *avpkt)
>>>>> +{
>>>>> + ARBCContext *s = avctx->priv_data;
>>>>> + AVFrame *const frame = data;
>>>>
>>>> No const.
>>>
>>> Will remove.
>>>
>>>>
>>>>> + int ret, nb_segments, keyframe = 1;
>>>>> +
>>>>> + if (avpkt->size < 1)
>>>>> + return AVERROR_INVALIDDATA;
>>>>> +
>>>>> + if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) <
>>>>> 0)
>>>>> + return ret;
>>>>> +
>>>>> + if (s->prev_frame->data[0]) {
>>>>> + ret = av_frame_copy(frame, s->prev_frame);
>>>>> + if (ret < 0)
>>>>> + return ret;
>>>>> + }
>>>>> +
>>>>> + bytestream2_init(&s->gb, avpkt->data, avpkt->size);
>>>>> + bytestream2_skip(&s->gb, 8);
>>>>> + nb_segments = bytestream2_get_le16(&s->gb);
>>>>> + if (nb_segments == 0)
>>>>> + keyframe = 0;
>>>>> +
>>>>> + for (int i = 0; i < nb_segments; i++) {
>>>>> + int resolution_flag;
>>>>> + uint8_t fill[3];
>>>>> +
>>>>> + if (bytestream2_get_bytes_left(&s->gb) <= 0)
>>>>> + return AVERROR_INVALIDDATA;
>>>>> +
>>>>> + fill[0] = bytestream2_get_byte(&s->gb);
>>>>> + bytestream2_skip(&s->gb, 1);
>>>>> + fill[1] = bytestream2_get_byte(&s->gb);
>>>>> + bytestream2_skip(&s->gb, 1);
>>>>> + fill[2] = bytestream2_get_byte(&s->gb);
>>>>> + bytestream2_skip(&s->gb, 1);
>>>>> + resolution_flag = bytestream2_get_byte(&s->gb);
>>>>> +
>>>>> + if (resolution_flag & 0x10)
>>>>> + fill_tileX(avctx, 1024, 1024, fill, frame);
>>>>> + if (resolution_flag & 0x08)
>>>>> + fill_tileX(avctx, 256, 256, fill, frame);
>>>>> + if (resolution_flag & 0x04)
>>>>> + fill_tileX(avctx, 64, 64, fill, frame);
>>>>> + if (resolution_flag & 0x02)
>>>>> + fill_tileX(avctx, 16, 16, fill, frame);
>>>>> + if (resolution_flag & 0x01)
>>>>> + fill_tile4(avctx, fill, frame);
>>>>> + }
>>>>> +
>>>>> + av_frame_unref(s->prev_frame);
>>>>> + if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
>>>>> + return ret;
>>>>> +
>>>>> + frame->pict_type = keyframe ? AV_PICTURE_TYPE_I :
>>>>> AV_PICTURE_TYPE_P;
>>>>> + frame->key_frame = keyframe;
>>>>> + *got_frame = 1;
>>>>> +
>>>>> + return avpkt->size;
>>>>> +}
>>>>> +
>>>>> +static av_cold int decode_init(AVCodecContext *avctx)
>>>>> +{
>>>>> + ARBCContext *s = avctx->priv_data;
>>>>> +
>>>>> + avctx->pix_fmt = AV_PIX_FMT_RGB24;
>>>>> +
>>>>> + s->prev_frame = av_frame_alloc();
>>>>> + if (!s->prev_frame)
>>>>> + return AVERROR(ENOMEM);
>>>>> +
>>>>> + return 0;
>>>>> +}
>>>>> +
>>>>> +static av_cold int decode_close(AVCodecContext *avctx)
>>>>> +{
>>>>> + ARBCContext *s = avctx->priv_data;
>>>>> +
>>>>> + av_frame_free(&s->prev_frame);
>>>>> +
>>>>> + return 0;
>>>>> +}
>>>>> +
>>>>> +AVCodec ff_arbc_decoder = {
>>>>> + .name = "arbc",
>>>>> + .long_name = NULL_IF_CONFIG_SMALL("Gryphon's Anim
>>>>> Compressor"),
>>>>> + .type = AVMEDIA_TYPE_VIDEO,
>>>>> + .id = AV_CODEC_ID_ARBC,
>>>>> + .priv_data_size = sizeof(ARBCContext),
>>>>> + .init = decode_init,
>>>>> + .decode = decode_frame,
>>>>> + .close = decode_close,
>>>>> + .capabilities = AV_CODEC_CAP_DR1,
>>>>> + .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
>>>>> + FF_CODEC_CAP_INIT_CLEANUP,
>>>>
>>>> No need for this one. Only s->prev_frame is allocated in init(), and if
>>>> that fails then close() would do nothing.
>>>
>>> What? Nonsense.
>>
>> INIT_CLEANUP is a flag to tell avcodec_open2() to call AVCodec.close()
>> if AVCodec.init() fails. Since s->prev_frame is the only thing allocated
>> by init(), calling close() after that failed to allocate is pointless.
>> s->prev_frame will be NULL and close() will be essentially a nop.
>
> So you do not like this flag being present here? It does not hurt to
> have it though.
It doesn't hurt, but it's also not proper. If someone were to use this
code as a reference implementation of the flag (grepping the tree for
examples), they'd get the wrong idea.
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