Support the Hap chunked frame format
[libav.git] / libavcodec / hapenc.c
1 /*
2 * Vidvox Hap encoder
3 * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
4 * Copyright (C) 2015 Tom Butterworth <bangnoise@gmail.com>
5 *
6 * This file is part of Libav.
7 *
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 /**
24 * @file
25 * Hap encoder
26 *
27 * Fourcc: Hap1, Hap5, HapY
28 *
29 * https://github.com/Vidvox/hap/blob/master/documentation/HapVideoDRAFT.md
30 */
31
32 #include <stdint.h>
33 #include "snappy-c.h"
34
35 #include "libavutil/frame.h"
36 #include "libavutil/imgutils.h"
37 #include "libavutil/intreadwrite.h"
38 #include "libavutil/opt.h"
39
40 #include "avcodec.h"
41 #include "bytestream.h"
42 #include "hap.h"
43 #include "internal.h"
44 #include "texturedsp.h"
45
46 #define HAP_MAX_CHUNKS 64
47
48 enum HapHeaderLength {
49 /* Short header: four bytes with a 24 bit size value */
50 HAP_HDR_SHORT = 4,
51 /* Long header: eight bytes with a 32 bit size value */
52 HAP_HDR_LONG = 8,
53 };
54
55 static void compress_texture(AVCodecContext *avctx, const AVFrame *f)
56 {
57 HapContext *ctx = avctx->priv_data;
58 uint8_t *out = ctx->tex_buf;
59 int i, j;
60
61 for (j = 0; j < avctx->height; j += 4) {
62 for (i = 0; i < avctx->width; i += 4) {
63 uint8_t *p = f->data[0] + i * 4 + j * f->linesize[0];
64 const int step = ctx->tex_fun(out, f->linesize[0], p);
65 out += step;
66 }
67 }
68 }
69
70 /* section_length does not include the header */
71 static void hap_write_section_header(PutByteContext *pbc,
72 enum HapHeaderLength header_length,
73 int section_length,
74 enum HapSectionType section_type)
75 {
76 /* The first three bytes are the length of the section (not including the
77 * header) or zero if using an eight-byte header.
78 * For an eight-byte header, the length is in the last four bytes.
79 * The fourth byte stores the section type. */
80 bytestream2_put_le24(pbc, header_length == HAP_HDR_LONG ? 0 : section_length);
81 bytestream2_put_byte(pbc, section_type);
82
83 if (header_length == HAP_HDR_LONG) {
84 bytestream2_put_le32(pbc, section_length);
85 }
86 }
87
88 static int hap_compress_frame(AVCodecContext *avctx, uint8_t *dst)
89 {
90 HapContext *ctx = avctx->priv_data;
91 int i, final_size = 0;
92
93 for (i = 0; i < ctx->chunk_count; i++) {
94 HapChunk *chunk = &ctx->chunks[i];
95 uint8_t *chunk_src, *chunk_dst;
96 int ret;
97
98 if (i == 0) {
99 chunk->compressed_offset = 0;
100 } else {
101 chunk->compressed_offset = ctx->chunks[i-1].compressed_offset
102 + ctx->chunks[i-1].compressed_size;
103 }
104 chunk->uncompressed_size = ctx->tex_size / ctx->chunk_count;
105 chunk->uncompressed_offset = i * chunk->uncompressed_size;
106 chunk->compressed_size = ctx->max_snappy;
107 chunk_src = ctx->tex_buf + chunk->uncompressed_offset;
108 chunk_dst = dst + chunk->compressed_offset;
109
110 /* Compress with snappy too, write directly on packet buffer. */
111 ret = snappy_compress(chunk_src, chunk->uncompressed_size,
112 chunk_dst, &chunk->compressed_size);
113 if (ret != SNAPPY_OK) {
114 av_log(avctx, AV_LOG_ERROR, "Snappy compress error.\n");
115 return AVERROR_BUG;
116 }
117
118 /* If there is no gain from snappy, just use the raw texture. */
119 if (chunk->compressed_size >= chunk->uncompressed_size) {
120 av_log(avctx, AV_LOG_VERBOSE,
121 "Snappy buffer bigger than uncompressed (%lu >= %lu bytes).\n",
122 chunk->compressed_size, chunk->uncompressed_size);
123 memcpy(chunk_dst, chunk_src, chunk->uncompressed_size);
124 chunk->compressor = HAP_COMP_NONE;
125 chunk->compressed_size = chunk->uncompressed_size;
126 } else {
127 chunk->compressor = HAP_COMP_SNAPPY;
128 }
129
130 final_size += chunk->compressed_size;
131 }
132
133 return final_size;
134 }
135
136 static int hap_decode_instructions_length(HapContext *ctx)
137 {
138 /* Second-Stage Compressor Table (one byte per entry)
139 * + Chunk Size Table (four bytes per entry)
140 * + headers for both sections (short versions)
141 * = chunk_count + (4 * chunk_count) + 4 + 4 */
142 return (5 * ctx->chunk_count) + 8;
143 }
144
145 static int hap_header_length(HapContext *ctx)
146 {
147 /* Top section header (long version) */
148 int length = HAP_HDR_LONG;
149
150 if (ctx->chunk_count > 1) {
151 /* Decode Instructions header (short) + Decode Instructions Container */
152 length += HAP_HDR_SHORT + hap_decode_instructions_length(ctx);
153 }
154
155 return length;
156 }
157
158 static void hap_write_frame_header(HapContext *ctx, uint8_t *dst, int frame_length)
159 {
160 PutByteContext pbc;
161 int i;
162
163 bytestream2_init_writer(&pbc, dst, frame_length);
164 if (ctx->chunk_count == 1) {
165 /* Write a simple header */
166 hap_write_section_header(&pbc, HAP_HDR_LONG, frame_length - 8,
167 ctx->chunks[0].compressor | ctx->opt_tex_fmt);
168 } else {
169 /* Write a complex header with Decode Instructions Container */
170 hap_write_section_header(&pbc, HAP_HDR_LONG, frame_length - 8,
171 HAP_COMP_COMPLEX | ctx->opt_tex_fmt);
172 hap_write_section_header(&pbc, HAP_HDR_SHORT, hap_decode_instructions_length(ctx),
173 HAP_ST_DECODE_INSTRUCTIONS);
174 hap_write_section_header(&pbc, HAP_HDR_SHORT, ctx->chunk_count,
175 HAP_ST_COMPRESSOR_TABLE);
176
177 for (i = 0; i < ctx->chunk_count; i++) {
178 bytestream2_put_byte(&pbc, ctx->chunks[i].compressor >> 4);
179 }
180
181 hap_write_section_header(&pbc, HAP_HDR_SHORT, ctx->chunk_count * 4,
182 HAP_ST_SIZE_TABLE);
183
184 for (i = 0; i < ctx->chunk_count; i++) {
185 bytestream2_put_le32(&pbc, ctx->chunks[i].compressed_size);
186 }
187 }
188 }
189
190 static int hap_encode(AVCodecContext *avctx, AVPacket *pkt,
191 const AVFrame *frame, int *got_packet)
192 {
193 HapContext *ctx = avctx->priv_data;
194 int header_length = hap_header_length(ctx);
195 int final_data_size, ret;
196 int pktsize = FFMAX(ctx->tex_size, ctx->max_snappy * ctx->chunk_count) + header_length;
197
198 /* Allocate maximum size packet, shrink later. */
199 ret = ff_alloc_packet(pkt, pktsize);
200 if (ret < 0)
201 return ret;
202
203 /* DXTC compression. */
204 compress_texture(avctx, frame);
205
206 /* Compress (using Snappy) the frame */
207 final_data_size = hap_compress_frame(avctx, pkt->data + header_length);
208 if (final_data_size < 0)
209 return final_data_size;
210
211 /* Write header at the start. */
212 hap_write_frame_header(ctx, pkt->data, final_data_size + header_length);
213
214 av_shrink_packet(pkt, final_data_size + header_length);
215 pkt->flags |= AV_PKT_FLAG_KEY;
216 *got_packet = 1;
217 return 0;
218 }
219
220 static av_cold int hap_init(AVCodecContext *avctx)
221 {
222 HapContext *ctx = avctx->priv_data;
223 int ratio;
224 int corrected_chunk_count;
225 int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
226
227 if (ret < 0) {
228 av_log(avctx, AV_LOG_ERROR, "Invalid video size %dx%d.\n",
229 avctx->width, avctx->height);
230 return ret;
231 }
232
233 if (avctx->width % 4 || avctx->height % 4) {
234 av_log(avctx, AV_LOG_ERROR, "Video size %dx%d is not multiple of 4.\n",
235 avctx->width, avctx->height);
236 return AVERROR_INVALIDDATA;
237 }
238
239 ff_texturedspenc_init(&ctx->dxtc);
240
241 switch (ctx->opt_tex_fmt) {
242 case HAP_FMT_RGBDXT1:
243 ratio = 8;
244 avctx->codec_tag = MKTAG('H', 'a', 'p', '1');
245 ctx->tex_fun = ctx->dxtc.dxt1_block;
246 break;
247 case HAP_FMT_RGBADXT5:
248 ratio = 4;
249 avctx->codec_tag = MKTAG('H', 'a', 'p', '5');
250 ctx->tex_fun = ctx->dxtc.dxt5_block;
251 break;
252 case HAP_FMT_YCOCGDXT5:
253 ratio = 4;
254 avctx->codec_tag = MKTAG('H', 'a', 'p', 'Y');
255 ctx->tex_fun = ctx->dxtc.dxt5ys_block;
256 break;
257 default:
258 av_log(avctx, AV_LOG_ERROR, "Invalid format %02X\n", ctx->opt_tex_fmt);
259 return AVERROR_INVALIDDATA;
260 }
261
262 /* Texture compression ratio is constant, so can we computer
263 * beforehand the final size of the uncompressed buffer. */
264 ctx->tex_size = FFALIGN(avctx->width, TEXTURE_BLOCK_W) *
265 FFALIGN(avctx->height, TEXTURE_BLOCK_H) * 4 / ratio;
266
267 /* Round the chunk count to divide evenly on DXT block edges */
268 corrected_chunk_count = av_clip(ctx->opt_chunk_count, 1, HAP_MAX_CHUNKS);
269 while ((ctx->tex_size / (64 / ratio)) % corrected_chunk_count != 0) {
270 corrected_chunk_count--;
271 }
272 if (corrected_chunk_count != ctx->opt_chunk_count) {
273 av_log(avctx, AV_LOG_INFO, "%d chunks requested but %d used.\n",
274 ctx->opt_chunk_count, corrected_chunk_count);
275 }
276 ret = ff_hap_set_chunk_count(ctx, corrected_chunk_count, 1);
277 if (ret != 0)
278 return ret;
279
280 ctx->max_snappy = snappy_max_compressed_length(ctx->tex_size / corrected_chunk_count);
281
282 ctx->tex_buf = av_malloc(ctx->tex_size);
283 if (!ctx->tex_buf)
284 return AVERROR(ENOMEM);
285
286 return 0;
287 }
288
289 static av_cold int hap_close(AVCodecContext *avctx)
290 {
291 HapContext *ctx = avctx->priv_data;
292
293 ff_hap_free_context(ctx);
294
295 return 0;
296 }
297
298 #define OFFSET(x) offsetof(HapContext, x)
299 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
300 static const AVOption options[] = {
301 { "format", NULL, OFFSET(opt_tex_fmt), AV_OPT_TYPE_INT, { .i64 = HAP_FMT_RGBDXT1 }, HAP_FMT_RGBDXT1, HAP_FMT_YCOCGDXT5, FLAGS, "format" },
302 { "hap", "Hap 1 (DXT1 textures)", 0, AV_OPT_TYPE_CONST, { .i64 = HAP_FMT_RGBDXT1 }, 0, 0, FLAGS, "format" },
303 { "hap_alpha", "Hap Alpha (DXT5 textures)", 0, AV_OPT_TYPE_CONST, { .i64 = HAP_FMT_RGBADXT5 }, 0, 0, FLAGS, "format" },
304 { "hap_q", "Hap Q (DXT5-YCoCg textures)", 0, AV_OPT_TYPE_CONST, { .i64 = HAP_FMT_YCOCGDXT5 }, 0, 0, FLAGS, "format" },
305 { "chunks", "chunk count", OFFSET(opt_chunk_count), AV_OPT_TYPE_INT, {.i64 = 1 }, 1, HAP_MAX_CHUNKS, FLAGS, },
306 { NULL },
307 };
308
309 static const AVClass hapenc_class = {
310 .class_name = "Hap encoder",
311 .item_name = av_default_item_name,
312 .option = options,
313 .version = LIBAVUTIL_VERSION_INT,
314 };
315
316 AVCodec ff_hap_encoder = {
317 .name = "hap",
318 .long_name = NULL_IF_CONFIG_SMALL("Vidvox Hap encoder"),
319 .type = AVMEDIA_TYPE_VIDEO,
320 .id = AV_CODEC_ID_HAP,
321 .priv_data_size = sizeof(HapContext),
322 .priv_class = &hapenc_class,
323 .init = hap_init,
324 .encode2 = hap_encode,
325 .close = hap_close,
326 .pix_fmts = (const enum AVPixelFormat[]) {
327 AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE,
328 },
329 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
330 FF_CODEC_CAP_INIT_CLEANUP,
331 };