FFmpeg: libavcodec/libtheoraenc.c Source File

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libtheoraenc.c

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1 /*

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 */

21 /**

22 * @file

23 * @brief Theora encoder using libtheora.

24 * @author Paul Richards <paul.richards@gmail.com>

25 *

26 * A lot of this is copy / paste from other output codecs in

27 * libavcodec or pure guesswork (or both).

28 *

29 * I have used t_ prefixes on variables which are libtheora types

30 * and o_ prefixes on variables which are libogg types.

31 */

33 /* FFmpeg includes */

34 #include "libavutil/common.h"

35 #include "libavutil/intreadwrite.h"

36 #include "libavutil/pixdesc.h"

37 #include "libavutil/log.h"

38 #include "libavutil/base64.h"

39 #include "avcodec.h"

40 #include "internal.h"

42 /* libtheora includes */

43 #include <theora/theoraenc.h>

45 typedef struct TheoraContext {

46 th_enc_ctx *t_state;

47 uint8_t *stats;

48 int stats_size;

49 int stats_offset;

50 int uv_hshift;

51 int uv_vshift;

52 int keyframe_mask;

53 } TheoraContext;

55 /** Concatenate an ogg_packet into the extradata. */

56 static int concatenate_packet(unsigned int* offset,

57 AVCodecContext* avc_context,

58 const ogg_packet* packet)

59 {

60 const char* message = NULL;

61 int newsize = avc_context->extradata_size + 2 + packet->bytes;

62 int err = AVERROR_INVALIDDATA;

64 if (packet->bytes < 0) {

65 message = "ogg_packet has negative size";

66 } else if (packet->bytes > 0xffff) {

67 message = "ogg_packet is larger than 65535 bytes";

68 } else if (newsize < avc_context->extradata_size) {

69 message = "extradata_size would overflow";

70 } else {

71 if ((err = av_reallocp(&avc_context->extradata, newsize)) < 0) {

72 avc_context->extradata_size = 0;

73 message = "av_realloc failed";

74 }

75 }

76 if (message) {

77 av_log(avc_context, AV_LOG_ERROR, "concatenate_packet failed: %s\n", message);

78 return err;

79 }

81 avc_context->extradata_size = newsize;

82 AV_WB16(avc_context->extradata + (*offset), packet->bytes);

83 *offset += 2;

84 memcpy(avc_context->extradata + (*offset), packet->packet, packet->bytes);

85 (*offset) += packet->bytes;

86 return 0;

87 }

89 static int get_stats(AVCodecContext *avctx, int eos)

90 {

91 #ifdef TH_ENCCTL_2PASS_OUT

92 TheoraContext *h = avctx->priv_data;

93 uint8_t *buf;

94 int bytes;

96 bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_OUT, &buf, sizeof(buf));

97 if (bytes < 0) {

98 av_log(avctx, AV_LOG_ERROR, "Error getting first pass stats\n");

99 return AVERROR_EXTERNAL;

100 }

101 if (!eos) {

102 h->stats = av_fast_realloc(h->stats, &h->stats_size,

103 h->stats_offset + bytes);

104 memcpy(h->stats + h->stats_offset, buf, bytes);

105 h->stats_offset += bytes;

106 } else {

107 int b64_size = AV_BASE64_SIZE(h->stats_offset);

108 // libtheora generates a summary header at the end

109 memcpy(h->stats, buf, bytes);

110 avctx->stats_out = av_malloc(b64_size);

111 av_base64_encode(avctx->stats_out, b64_size, h->stats, h->stats_offset);

112 }

113 return 0;

114 #else

115 av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");

116 return AVERROR(ENOSUP);

117 #endif

118 }

119

120 // libtheora won't read the entire buffer we give it at once, so we have to

121 // repeatedly submit it...

122 static int submit_stats(AVCodecContext *avctx)

123 {

124 #ifdef TH_ENCCTL_2PASS_IN

125 TheoraContext *h = avctx->priv_data;

126 int bytes;

127 if (!h->stats) {

128 if (!avctx->stats_in) {

129 av_log(avctx, AV_LOG_ERROR, "No statsfile for second pass\n");

130 return AVERROR(EINVAL);

131 }

132 h->stats_size = strlen(avctx->stats_in) * 3/4;

133 h->stats = av_malloc(h->stats_size);

134 h->stats_size = av_base64_decode(h->stats, avctx->stats_in, h->stats_size);

135 }

136 while (h->stats_size - h->stats_offset > 0) {

137 bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_IN,

138 h->stats + h->stats_offset,

139 h->stats_size - h->stats_offset);

140 if (bytes < 0) {

141 av_log(avctx, AV_LOG_ERROR, "Error submitting stats\n");

142 return AVERROR_EXTERNAL;

143 }

144 if (!bytes)

145 return 0;

146 h->stats_offset += bytes;

147 }

148 return 0;

149 #else

150 av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");

151 return AVERROR(ENOSUP);

152 #endif

153 }

154

155 static av_cold int encode_init(AVCodecContext* avc_context)

156 {

157 th_info t_info;

158 th_comment t_comment;

159 ogg_packet o_packet;

160 unsigned int offset;

161 TheoraContext *h = avc_context->priv_data;

162 uint32_t gop_size = avc_context->gop_size;

163 int ret;

164

165 /* Set up the theora_info struct */

166 th_info_init(&t_info);

167 t_info.frame_width = FFALIGN(avc_context->width, 16);

168 t_info.frame_height = FFALIGN(avc_context->height, 16);

169 t_info.pic_width = avc_context->width;

170 t_info.pic_height = avc_context->height;

171 t_info.pic_x = 0;

172 t_info.pic_y = 0;

173 /* Swap numerator and denominator as time_base in AVCodecContext gives the

174 * time period between frames, but theora_info needs the framerate. */

175 t_info.fps_numerator = avc_context->time_base.den;

176 t_info.fps_denominator = avc_context->time_base.num;

177 if (avc_context->sample_aspect_ratio.num) {

178 t_info.aspect_numerator = avc_context->sample_aspect_ratio.num;

179 t_info.aspect_denominator = avc_context->sample_aspect_ratio.den;

180 } else {

181 t_info.aspect_numerator = 1;

182 t_info.aspect_denominator = 1;

183 }

184

185 if (avc_context->color_primaries == AVCOL_PRI_BT470M)

186 t_info.colorspace = TH_CS_ITU_REC_470M;

187 else if (avc_context->color_primaries == AVCOL_PRI_BT470BG)

188 t_info.colorspace = TH_CS_ITU_REC_470BG;

189 else

190 t_info.colorspace = TH_CS_UNSPECIFIED;

191

192 if (avc_context->pix_fmt == AV_PIX_FMT_YUV420P)

193 t_info.pixel_fmt = TH_PF_420;

194 else if (avc_context->pix_fmt == AV_PIX_FMT_YUV422P)

195 t_info.pixel_fmt = TH_PF_422;

196 else if (avc_context->pix_fmt == AV_PIX_FMT_YUV444P)

197 t_info.pixel_fmt = TH_PF_444;

198 else {

199 av_log(avc_context, AV_LOG_ERROR, "Unsupported pix_fmt\n");

200 return AVERROR(EINVAL);

201 }

202 avcodec_get_chroma_sub_sample(avc_context->pix_fmt, &h->uv_hshift, &h->uv_vshift);

203

204 if (avc_context->flags & CODEC_FLAG_QSCALE) {

205 /* Clip global_quality in QP units to the [0 - 10] range

206 to be consistent with the libvorbis implementation.

207 Theora accepts a quality parameter which is an int value in

208 the [0 - 63] range.

209 */

210 t_info.quality = av_clipf(avc_context->global_quality / (float)FF_QP2LAMBDA, 0, 10) * 6.3;

211 t_info.target_bitrate = 0;

212 } else {

213 t_info.target_bitrate = avc_context->bit_rate;

214 t_info.quality = 0;

215 }

216

217 /* Now initialise libtheora */

218 h->t_state = th_encode_alloc(&t_info);

219 if (!h->t_state) {

220 av_log(avc_context, AV_LOG_ERROR, "theora_encode_init failed\n");

221 return AVERROR_EXTERNAL;

222 }

223

224 h->keyframe_mask = (1 << t_info.keyframe_granule_shift) - 1;

225 /* Clear up theora_info struct */

226 th_info_clear(&t_info);

227

228 if (th_encode_ctl(h->t_state, TH_ENCCTL_SET_KEYFRAME_FREQUENCY_FORCE,

229 &gop_size, sizeof(gop_size))) {

230 av_log(avc_context, AV_LOG_ERROR, "Error setting GOP size\n");

231 return AVERROR_EXTERNAL;

232 }

233

234 // need to enable 2 pass (via TH_ENCCTL_2PASS_) before encoding headers

235 if (avc_context->flags & CODEC_FLAG_PASS1) {

236 if ((ret = get_stats(avc_context, 0)) < 0)

237 return ret;

238 } else if (avc_context->flags & CODEC_FLAG_PASS2) {

239 if ((ret = submit_stats(avc_context)) < 0)

240 return ret;

241 }

242

243 /*

244 Output first header packet consisting of theora

245 header, comment, and tables.

246

247 Each one is prefixed with a 16bit size, then they

248 are concatenated together into libavcodec's extradata.

249 */

250 offset = 0;

251

252 /* Headers */

253 th_comment_init(&t_comment);

254

255 while (th_encode_flushheader(h->t_state, &t_comment, &o_packet))

256 if ((ret = concatenate_packet(&offset, avc_context, &o_packet)) < 0)

257 return ret;

258

259 th_comment_clear(&t_comment);

260

261 /* Set up the output AVFrame */

262 avc_context->coded_frame = av_frame_alloc();

263

264 return 0;

265 }

266

267 static int encode_frame(AVCodecContext* avc_context, AVPacket *pkt,

268 const AVFrame *frame, int *got_packet)

269 {

270 th_ycbcr_buffer t_yuv_buffer;

271 TheoraContext *h = avc_context->priv_data;

272 ogg_packet o_packet;

273 int result, i, ret;

274

275 // EOS, finish and get 1st pass stats if applicable

276 if (!frame) {

277 th_encode_packetout(h->t_state, 1, &o_packet);

278 if (avc_context->flags & CODEC_FLAG_PASS1)

279 if ((ret = get_stats(avc_context, 1)) < 0)

280 return ret;

281 return 0;

282 }

283

284 /* Copy planes to the theora yuv_buffer */

285 for (i = 0; i < 3; i++) {

286 t_yuv_buffer[i].width = FFALIGN(avc_context->width, 16) >> (i && h->uv_hshift);

287 t_yuv_buffer[i].height = FFALIGN(avc_context->height, 16) >> (i && h->uv_vshift);

288 t_yuv_buffer[i].stride = frame->linesize[i];

289 t_yuv_buffer[i].data = frame->data[i];

290 }

291

292 if (avc_context->flags & CODEC_FLAG_PASS2)

293 if ((ret = submit_stats(avc_context)) < 0)

294 return ret;

295

296 /* Now call into theora_encode_YUVin */

297 result = th_encode_ycbcr_in(h->t_state, t_yuv_buffer);

298 if (result) {

299 const char* message;

300 switch (result) {

301 case -1:

302 message = "differing frame sizes";

303 break;

304 case TH_EINVAL:

305 message = "encoder is not ready or is finished";

306 break;

307 default:

308 message = "unknown reason";

309 break;

310 }

311 av_log(avc_context, AV_LOG_ERROR, "theora_encode_YUVin failed (%s) [%d]\n", message, result);

312 return AVERROR_EXTERNAL;

313 }

314

315 if (avc_context->flags & CODEC_FLAG_PASS1)

316 if ((ret = get_stats(avc_context, 0)) < 0)

317 return ret;

318

319 /* Pick up returned ogg_packet */

320 result = th_encode_packetout(h->t_state, 0, &o_packet);

321 switch (result) {

322 case 0:

323 /* No packet is ready */

324 return 0;

325 case 1:

326 /* Success, we have a packet */

327 break;

328 default:

329 av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed [%d]\n", result);

330 return AVERROR_EXTERNAL;

331 }

332

333 /* Copy ogg_packet content out to buffer */

334 if ((ret = ff_alloc_packet2(avc_context, pkt, o_packet.bytes)) < 0)

335 return ret;

336 memcpy(pkt->data, o_packet.packet, o_packet.bytes);

337

338 // HACK: assumes no encoder delay, this is true until libtheora becomes

339 // multithreaded (which will be disabled unless explicitly requested)

340 pkt->pts = pkt->dts = frame->pts;

341 avc_context->coded_frame->key_frame = !(o_packet.granulepos & h->keyframe_mask);

342 if (avc_context->coded_frame->key_frame)

343 pkt->flags |= AV_PKT_FLAG_KEY;

344 *got_packet = 1;

345

346 return 0;

347 }

348

349 static av_cold int encode_close(AVCodecContext* avc_context)

350 {

351 TheoraContext *h = avc_context->priv_data;

352

353 th_encode_free(h->t_state);

354 av_freep(&h->stats);

355 av_freep(&avc_context->coded_frame);

356 av_freep(&avc_context->stats_out);

357 av_freep(&avc_context->extradata);

358 avc_context->extradata_size = 0;

359

360 return 0;

361 }

362

363 /** AVCodec struct exposed to libavcodec */

364 AVCodec ff_libtheora_encoder = {

365 .name = "libtheora",

366 .long_name = NULL_IF_CONFIG_SMALL("libtheora Theora"),

367 .type = AVMEDIA_TYPE_VIDEO,

368 .id = AV_CODEC_ID_THEORA,

369 .priv_data_size = sizeof(TheoraContext),

370 .init = encode_init,

371 .close = encode_close,

372 .encode2 = encode_frame,

373 .capabilities = CODEC_CAP_DELAY, // needed to get the statsfile summary

374 .pix_fmts = (const enum AVPixelFormat[]){

375 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_NONE

376 },

377 };

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