libavcodec/libtheoraenc.c

   1 /*
   2  * Copyright (c) 2006 Paul Richards <paul.richards@gmail.com>
   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  */
  20
  21 /*!
  22  * \file libtheoraenc.c
  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  */
  32
  33 /* FFmpeg includes */
  34 #include "libavutil/intreadwrite.h"
  35 #include "libavutil/log.h"
  36 #include "avcodec.h"
  37
  38 /* libtheora includes */
  39 #include <theora/theora.h>
  40
  41 typedef struct TheoraContext{
  42     theora_state t_state;
  43 } TheoraContext;
  44
  45 /*!
  46     Concatenates an ogg_packet into the extradata.
  47 */
  48 static int concatenate_packet(unsigned int* offset, AVCodecContext* avc_context, const ogg_packet* packet)
  49 {
  50     char* message = NULL;
  51     uint8_t* newdata = NULL;
  52     int newsize = avc_context->extradata_size + 2 + packet->bytes;
  53
  54     if (packet->bytes < 0) {
  55         message = "ogg_packet has negative size";
  56     } else if (packet->bytes > 0xffff) {
  57         message = "ogg_packet is larger than 65535 bytes";
  58     } else if (newsize < avc_context->extradata_size) {
  59         message = "extradata_size would overflow";
  60     } else {
  61         newdata = av_realloc(avc_context->extradata, newsize);
  62         if (newdata == NULL) {
  63             message = "av_realloc failed";
  64         }
  65     }
  66     if (message != NULL) {
  67         av_log(avc_context, AV_LOG_ERROR, "concatenate_packet failed: %s\n", message);
  68         return -1;
  69     }
  70
  71     avc_context->extradata = newdata;
  72     avc_context->extradata_size = newsize;
  73     AV_WB16(avc_context->extradata + (*offset), packet->bytes);
  74     *offset += 2;
  75     memcpy( avc_context->extradata + (*offset), packet->packet, packet->bytes );
  76     (*offset) += packet->bytes;
  77     return 0;
  78 }
  79
  80 static av_cold int encode_init(AVCodecContext* avc_context)
  81 {
  82     theora_info t_info;
  83     theora_comment t_comment;
  84     ogg_packet o_packet;
  85     unsigned int offset;
  86     TheoraContext *h = avc_context->priv_data;
  87
  88     /* Set up the theora_info struct */
  89     theora_info_init( &t_info );
  90     t_info.width = FFALIGN(avc_context->width, 16);
  91     t_info.height = FFALIGN(avc_context->height, 16);
  92     t_info.frame_width = avc_context->width;
  93     t_info.frame_height = avc_context->height;
  94     t_info.offset_x = 0;
  95     t_info.offset_y = avc_context->height & 0xf;
  96     /* Swap numerator and denominator as time_base in AVCodecContext gives the
  97      * time period between frames, but theora_info needs the framerate.  */
  98     t_info.fps_numerator = avc_context->time_base.den;
  99     t_info.fps_denominator = avc_context->time_base.num;
 100     if (avc_context->sample_aspect_ratio.num != 0) {
 101         t_info.aspect_numerator = avc_context->sample_aspect_ratio.num;
 102         t_info.aspect_denominator = avc_context->sample_aspect_ratio.den;
 103     } else {
 104         t_info.aspect_numerator = 1;
 105         t_info.aspect_denominator = 1;
 106     }
 107     t_info.colorspace = OC_CS_UNSPECIFIED;
 108     t_info.pixelformat = OC_PF_420;
 109     t_info.target_bitrate = avc_context->bit_rate;
 110     t_info.keyframe_frequency = avc_context->gop_size;
 111     t_info.keyframe_frequency_force = avc_context->gop_size;
 112     t_info.keyframe_mindistance = avc_context->keyint_min;
 113     t_info.quality = 0;
 114
 115     t_info.quick_p = 1;
 116     t_info.dropframes_p = 0;
 117     t_info.keyframe_auto_p = 1;
 118     t_info.keyframe_data_target_bitrate = t_info.target_bitrate * 1.5;
 119     t_info.keyframe_auto_threshold = 80;
 120     t_info.noise_sensitivity = 1;
 121     t_info.sharpness = 0;
 122
 123     /* Now initialise libtheora */
 124     if (theora_encode_init( &(h->t_state), &t_info ) != 0) {
 125         av_log(avc_context, AV_LOG_ERROR, "theora_encode_init failed\n");
 126         return -1;
 127     }
 128
 129     /* Clear up theora_info struct */
 130     theora_info_clear( &t_info );
 131
 132     /*
 133         Output first header packet consisting of theora
 134         header, comment, and tables.
 135
 136         Each one is prefixed with a 16bit size, then they
 137         are concatenated together into ffmpeg's extradata.
 138     */
 139     offset = 0;
 140
 141     /* Header */
 142     theora_encode_header( &(h->t_state), &o_packet );
 143     if (concatenate_packet( &offset, avc_context, &o_packet ) != 0) {
 144         return -1;
 145     }
 146
 147     /* Comment */
 148     theora_comment_init( &t_comment );
 149     theora_encode_comment( &t_comment, &o_packet );
 150     if (concatenate_packet( &offset, avc_context, &o_packet ) != 0) {
 151         return -1;
 152     }
 153
 154     /* Tables */
 155     theora_encode_tables( &(h->t_state), &o_packet );
 156     if (concatenate_packet( &offset, avc_context, &o_packet ) != 0) {
 157         return -1;
 158     }
 159
 160     /* Clear up theora_comment struct */
 161     theora_comment_clear( &t_comment );
 162
 163     /* Set up the output AVFrame */
 164     avc_context->coded_frame= avcodec_alloc_frame();
 165
 166     return 0;
 167 }
 168
 169 static int encode_frame(
 170     AVCodecContext* avc_context,
 171     uint8_t *outbuf,
 172     int buf_size,
 173     void *data)
 174 {
 175     yuv_buffer t_yuv_buffer;
 176     TheoraContext *h = avc_context->priv_data;
 177     AVFrame *frame = data;
 178     ogg_packet o_packet;
 179     int result;
 180
 181     assert(avc_context->pix_fmt == PIX_FMT_YUV420P);
 182
 183     /* Copy planes to the theora yuv_buffer */
 184     if (frame->linesize[1] != frame->linesize[2]) {
 185         av_log(avc_context, AV_LOG_ERROR, "U and V stride differ\n");
 186         return -1;
 187     }
 188
 189     t_yuv_buffer.y_width = FFALIGN(avc_context->width, 16);
 190     t_yuv_buffer.y_height = FFALIGN(avc_context->height, 16);
 191     t_yuv_buffer.y_stride = frame->linesize[0];
 192     t_yuv_buffer.uv_width = t_yuv_buffer.y_width / 2;
 193     t_yuv_buffer.uv_height = t_yuv_buffer.y_height / 2;
 194     t_yuv_buffer.uv_stride = frame->linesize[1];
 195
 196     t_yuv_buffer.y = frame->data[0];
 197     t_yuv_buffer.u = frame->data[1];
 198     t_yuv_buffer.v = frame->data[2];
 199
 200     /* Now call into theora_encode_YUVin */
 201     result = theora_encode_YUVin( &(h->t_state), &t_yuv_buffer );
 202     if (result != 0) {
 203         const char* message;
 204         switch (result) {
 205             case -1:
 206                 message = "differing frame sizes";
 207                 break;
 208             case OC_EINVAL:
 209                 message = "encoder is not ready or is finished";
 210                 break;
 211             default:
 212                 message = "unknown reason";
 213                 break;
 214         }
 215         av_log(avc_context, AV_LOG_ERROR, "theora_encode_YUVin failed (%s) [%d]\n", message, result);
 216         return -1;
 217     }
 218
 219     /* Pick up returned ogg_packet */
 220     result = theora_encode_packetout( &(h->t_state), 0, &o_packet );
 221     switch (result) {
 222         case 0:
 223             /* No packet is ready */
 224             return 0;
 225         case 1:
 226             /* Success, we have a packet */
 227             break;
 228         default:
 229             av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed [%d]\n", result);
 230             return -1;
 231     }
 232
 233     /* Copy ogg_packet content out to buffer */
 234     if (buf_size < o_packet.bytes) {
 235         av_log(avc_context, AV_LOG_ERROR, "encoded frame too large\n");
 236         return -1;
 237     }
 238     memcpy(outbuf, o_packet.packet, o_packet.bytes);
 239
 240     return o_packet.bytes;
 241 }
 242
 243 static av_cold int encode_close(AVCodecContext* avc_context)
 244 {
 245     ogg_packet o_packet;
 246     TheoraContext *h = avc_context->priv_data;
 247     int result;
 248     const char* message;
 249
 250     result = theora_encode_packetout( &(h->t_state), 1, &o_packet );
 251     theora_clear( &(h->t_state) );
 252     switch (result) {
 253         case 0:/* No packet is ready */
 254         case -1:/* Encoding finished */
 255             return 0;
 256         case 1:
 257             /* We have a packet */
 258             message = "gave us a packet";
 259             break;
 260         default:
 261             message = "unknown reason";
 262             break;
 263     }
 264     av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed (%s) [%d]\n", message, result);
 265     return -1;
 266 }
 267
 268 static const enum PixelFormat supported_pixel_formats[] = { PIX_FMT_YUV420P, PIX_FMT_NONE };
 269
 270 /*! AVCodec struct exposed to libavcodec */
 271 AVCodec libtheora_encoder =
 272 {
 273     .name = "libtheora",
 274     .type = CODEC_TYPE_VIDEO,
 275     .id = CODEC_ID_THEORA,
 276     .priv_data_size = sizeof(TheoraContext),
 277     .init = encode_init,
 278     .close = encode_close,
 279     .encode = encode_frame,
 280     .pix_fmts = supported_pixel_formats,
 281     .long_name = NULL_IF_CONFIG_SMALL("libtheora Theora"),
 282 };