2 * Copyright (c) 2006 Paul Richards <paul.richards@gmail.com>
4 * This file is part of FFmpeg.
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.
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.
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 St, Fifth Floor, Boston, MA 02110-1301 USA
23 * \brief Theora encoder using libtheora.
24 * \author Paul Richards <paul.richards@gmail.com>
26 * A lot of this is copy / paste from other output codecs in
27 * libavcodec or pure guesswork (or both).
29 * I have used t_ prefixes on variables which are libtheora types
30 * and o_ prefixes on variables which are libogg types.
37 /* libtheora includes */
38 #include <theora/theora.h>
40 typedef struct TheoraContext{
45 Concatenates an ogg_packet into the extradata.
47 static int concatenate_packet(unsigned int* offset, AVCodecContext* avc_context, const ogg_packet* packet)
50 uint8_t* newdata = NULL;
51 int newsize = avc_context->extradata_size + 2 + packet->bytes;
53 if (packet->bytes < 0) {
54 message = "ogg_packet has negative size";
55 } else if (packet->bytes > 0xffff) {
56 message = "ogg_packet is larger than 65535 bytes";
57 } else if (newsize < avc_context->extradata_size) {
58 message = "extradata_size would overflow";
60 newdata = av_realloc(avc_context->extradata, newsize);
61 if (newdata == NULL) {
62 message = "av_realloc failed";
65 if (message != NULL) {
66 av_log(avc_context, AV_LOG_ERROR, "concatenate_packet failed: %s\n", message);
70 avc_context->extradata = newdata;
71 avc_context->extradata_size = newsize;
72 avc_context->extradata[ (*offset)++ ] = packet->bytes >> 8;
73 avc_context->extradata[ (*offset)++ ] = packet->bytes & 0xff;
74 memcpy( avc_context->extradata + (*offset), packet->packet, packet->bytes );
75 (*offset) += packet->bytes;
79 static int encode_init(AVCodecContext* avc_context)
82 theora_comment t_comment;
85 TheoraContext *h = avc_context->priv_data;
87 /* Set up the theora_info struct */
88 theora_info_init( &t_info );
89 t_info.width = avc_context->width;
90 t_info.height = avc_context->height;
91 t_info.frame_width = avc_context->width;
92 t_info.frame_height = avc_context->height;
95 /* Swap numerator and denominator as time_base in AVCodecContext gives the
96 * time period between frames, but theora_info needs the framerate. */
97 t_info.fps_numerator = avc_context->time_base.den;
98 t_info.fps_denominator = avc_context->time_base.num;
99 if (avc_context->sample_aspect_ratio.num != 0) {
100 t_info.aspect_numerator = avc_context->sample_aspect_ratio.num;
101 t_info.aspect_denominator = avc_context->sample_aspect_ratio.den;
103 t_info.aspect_numerator = 1;
104 t_info.aspect_denominator = 1;
106 t_info.colorspace = OC_CS_UNSPECIFIED;
107 t_info.pixelformat = OC_PF_420;
108 t_info.target_bitrate = avc_context->bit_rate;
109 t_info.keyframe_frequency = avc_context->gop_size;
110 t_info.keyframe_frequency_force = avc_context->gop_size;
111 t_info.keyframe_mindistance = avc_context->keyint_min;
115 t_info.dropframes_p = 0;
116 t_info.keyframe_auto_p = 1;
117 t_info.keyframe_data_target_bitrate = t_info.target_bitrate * 1.5;
118 t_info.keyframe_auto_threshold = 80;
119 t_info.noise_sensitivity = 1;
120 t_info.sharpness = 0;
122 /* Now initialise libtheora */
123 if (theora_encode_init( &(h->t_state), &t_info ) != 0) {
124 av_log(avc_context, AV_LOG_ERROR, "theora_encode_init failed\n");
128 /* Clear up theora_info struct */
129 theora_info_clear( &t_info );
132 Output first header packet consisting of theora
133 header, comment, and tables.
135 Each one is prefixed with a 16bit size, then they
136 are concatenated together into ffmpeg's extradata.
141 theora_encode_header( &(h->t_state), &o_packet );
142 if (concatenate_packet( &offset, avc_context, &o_packet ) != 0) {
147 theora_comment_init( &t_comment );
148 theora_encode_comment( &t_comment, &o_packet );
149 if (concatenate_packet( &offset, avc_context, &o_packet ) != 0) {
154 theora_encode_tables( &(h->t_state), &o_packet );
155 if (concatenate_packet( &offset, avc_context, &o_packet ) != 0) {
159 /* Clear up theora_comment struct */
160 theora_comment_clear( &t_comment );
162 /* Set up the output AVFrame */
163 avc_context->coded_frame= avcodec_alloc_frame();
168 static int encode_frame(
169 AVCodecContext* avc_context,
174 yuv_buffer t_yuv_buffer;
175 TheoraContext *h = avc_context->priv_data;
176 AVFrame *frame = data;
180 assert(avc_context->pix_fmt == PIX_FMT_YUV420P);
182 /* Copy planes to the theora yuv_buffer */
183 if (frame->linesize[1] != frame->linesize[2]) {
184 av_log(avc_context, AV_LOG_ERROR, "U and V stride differ\n");
188 t_yuv_buffer.y_width = avc_context->width;
189 t_yuv_buffer.y_height = avc_context->height;
190 t_yuv_buffer.y_stride = frame->linesize[0];
191 t_yuv_buffer.uv_width = t_yuv_buffer.y_width / 2;
192 t_yuv_buffer.uv_height = t_yuv_buffer.y_height / 2;
193 t_yuv_buffer.uv_stride = frame->linesize[1];
195 t_yuv_buffer.y = frame->data[0];
196 t_yuv_buffer.u = frame->data[1];
197 t_yuv_buffer.v = frame->data[2];
199 /* Now call into theora_encode_YUVin */
200 result = theora_encode_YUVin( &(h->t_state), &t_yuv_buffer );
205 message = "differing frame sizes";
208 message = "encoder is not ready or is finished";
211 message = "unknown reason";
214 av_log(avc_context, AV_LOG_ERROR, "theora_encode_YUVin failed (%s) [%d]\n", message, result);
218 /* Pick up returned ogg_packet */
219 result = theora_encode_packetout( &(h->t_state), 0, &o_packet );
222 /* No packet is ready */
225 /* Success, we have a packet */
228 av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed [%d]\n", result);
232 /* Copy ogg_packet content out to buffer */
233 if (buf_size < o_packet.bytes) {
234 av_log(avc_context, AV_LOG_ERROR, "encoded frame too large\n");
237 memcpy(outbuf, o_packet.packet, o_packet.bytes);
239 return o_packet.bytes;
242 static int encode_close(AVCodecContext* avc_context)
245 TheoraContext *h = avc_context->priv_data;
249 result = theora_encode_packetout( &(h->t_state), 1, &o_packet );
250 theora_clear( &(h->t_state) );
252 case 0:/* No packet is ready */
253 case -1:/* Encoding finished */
256 /* We have a packet */
257 message = "gave us a packet";
260 message = "unknown reason";
263 av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed (%s) [%d]\n", message, result);
267 static const enum PixelFormat supported_pixel_formats[] = { PIX_FMT_YUV420P, -1 };
269 /*! AVCodec struct exposed to libavcodec */
270 AVCodec libtheora_encoder =
273 .type = CODEC_TYPE_VIDEO,
274 .id = CODEC_ID_THEORA,
275 .priv_data_size = sizeof(TheoraContext),
277 .close = encode_close,
278 .encode = encode_frame,
279 .pix_fmts = supported_pixel_formats,