ffmpeg/libavcodec/libtheoraenc.c

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/*
* Copyright (c) 2006 Paul Richards <paul.richards@gmail.com>
*
* 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
*/
/*!
* \file theoraenc.c
* \brief Theora encoder using libtheora.
* \author Paul Richards <paul.richards@gmail.com>
*
* A lot of this is copy / paste from other output codecs in
* libavcodec or pure guesswork (or both).
*
* I have used t_ prefixes on variables which are libtheora types
* and o_ prefixes on variables which are libogg types.
*/
/* FFmpeg includes */
#include "avcodec.h"
#include "log.h"
/* libtheora includes */
#include <theora/theora.h>
typedef struct TheoraContext{
theora_state t_state;
} TheoraContext;
/*!
Concatenates an ogg_packet into the extradata.
*/
static int concatenate_packet(unsigned int* offset, AVCodecContext* avc_context, const ogg_packet* packet)
{
char* message = NULL;
uint8_t* newdata = NULL;
int newsize = avc_context->extradata_size + 2 + packet->bytes;
if (packet->bytes < 0) {
message = "ogg_packet has negative size";
} else if (packet->bytes > 0xffff) {
message = "ogg_packet is larger than 65535 bytes";
} else if (newsize < avc_context->extradata_size) {
message = "extradata_size would overflow";
} else {
newdata = av_realloc(avc_context->extradata, newsize);
if (newdata == NULL) {
message = "av_realloc failed";
}
}
if (message != NULL) {
av_log(avc_context, AV_LOG_ERROR, "concatenate_packet failed: %s\n", message);
return -1;
}
avc_context->extradata = newdata;
avc_context->extradata_size = newsize;
AV_WB16(avc_context->extradata + (*offset), packet->bytes);
*offset += 2;
memcpy( avc_context->extradata + (*offset), packet->packet, packet->bytes );
(*offset) += packet->bytes;
return 0;
}
static int encode_init(AVCodecContext* avc_context)
{
theora_info t_info;
theora_comment t_comment;
ogg_packet o_packet;
unsigned int offset;
TheoraContext *h = avc_context->priv_data;
/* Set up the theora_info struct */
theora_info_init( &t_info );
t_info.width = avc_context->width;
t_info.height = avc_context->height;
t_info.frame_width = avc_context->width;
t_info.frame_height = avc_context->height;
t_info.offset_x = 0;
t_info.offset_y = 0;
/* Swap numerator and denominator as time_base in AVCodecContext gives the
* time period between frames, but theora_info needs the framerate. */
t_info.fps_numerator = avc_context->time_base.den;
t_info.fps_denominator = avc_context->time_base.num;
if (avc_context->sample_aspect_ratio.num != 0) {
t_info.aspect_numerator = avc_context->sample_aspect_ratio.num;
t_info.aspect_denominator = avc_context->sample_aspect_ratio.den;
} else {
t_info.aspect_numerator = 1;
t_info.aspect_denominator = 1;
}
t_info.colorspace = OC_CS_UNSPECIFIED;
t_info.pixelformat = OC_PF_420;
t_info.target_bitrate = avc_context->bit_rate;
t_info.keyframe_frequency = avc_context->gop_size;
t_info.keyframe_frequency_force = avc_context->gop_size;
t_info.keyframe_mindistance = avc_context->keyint_min;
t_info.quality = 0;
t_info.quick_p = 1;
t_info.dropframes_p = 0;
t_info.keyframe_auto_p = 1;
t_info.keyframe_data_target_bitrate = t_info.target_bitrate * 1.5;
t_info.keyframe_auto_threshold = 80;
t_info.noise_sensitivity = 1;
t_info.sharpness = 0;
/* Now initialise libtheora */
if (theora_encode_init( &(h->t_state), &t_info ) != 0) {
av_log(avc_context, AV_LOG_ERROR, "theora_encode_init failed\n");
return -1;
}
/* Clear up theora_info struct */
theora_info_clear( &t_info );
/*
Output first header packet consisting of theora
header, comment, and tables.
Each one is prefixed with a 16bit size, then they
are concatenated together into ffmpeg's extradata.
*/
offset = 0;
/* Header */
theora_encode_header( &(h->t_state), &o_packet );
if (concatenate_packet( &offset, avc_context, &o_packet ) != 0) {
return -1;
}
/* Comment */
theora_comment_init( &t_comment );
theora_encode_comment( &t_comment, &o_packet );
if (concatenate_packet( &offset, avc_context, &o_packet ) != 0) {
return -1;
}
/* Tables */
theora_encode_tables( &(h->t_state), &o_packet );
if (concatenate_packet( &offset, avc_context, &o_packet ) != 0) {
return -1;
}
/* Clear up theora_comment struct */
theora_comment_clear( &t_comment );
/* Set up the output AVFrame */
avc_context->coded_frame= avcodec_alloc_frame();
return 0;
}
static int encode_frame(
AVCodecContext* avc_context,
uint8_t *outbuf,
int buf_size,
void *data)
{
yuv_buffer t_yuv_buffer;
TheoraContext *h = avc_context->priv_data;
AVFrame *frame = data;
ogg_packet o_packet;
int result;
assert(avc_context->pix_fmt == PIX_FMT_YUV420P);
/* Copy planes to the theora yuv_buffer */
if (frame->linesize[1] != frame->linesize[2]) {
av_log(avc_context, AV_LOG_ERROR, "U and V stride differ\n");
return -1;
}
t_yuv_buffer.y_width = avc_context->width;
t_yuv_buffer.y_height = avc_context->height;
t_yuv_buffer.y_stride = frame->linesize[0];
t_yuv_buffer.uv_width = t_yuv_buffer.y_width / 2;
t_yuv_buffer.uv_height = t_yuv_buffer.y_height / 2;
t_yuv_buffer.uv_stride = frame->linesize[1];
t_yuv_buffer.y = frame->data[0];
t_yuv_buffer.u = frame->data[1];
t_yuv_buffer.v = frame->data[2];
/* Now call into theora_encode_YUVin */
result = theora_encode_YUVin( &(h->t_state), &t_yuv_buffer );
if (result != 0) {
const char* message;
switch (result) {
case -1:
message = "differing frame sizes";
break;
case OC_EINVAL:
message = "encoder is not ready or is finished";
break;
default:
message = "unknown reason";
break;
}
av_log(avc_context, AV_LOG_ERROR, "theora_encode_YUVin failed (%s) [%d]\n", message, result);
return -1;
}
/* Pick up returned ogg_packet */
result = theora_encode_packetout( &(h->t_state), 0, &o_packet );
switch (result) {
case 0:
/* No packet is ready */
return 0;
case 1:
/* Success, we have a packet */
break;
default:
av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed [%d]\n", result);
return -1;
}
/* Copy ogg_packet content out to buffer */
if (buf_size < o_packet.bytes) {
av_log(avc_context, AV_LOG_ERROR, "encoded frame too large\n");
return -1;
}
memcpy(outbuf, o_packet.packet, o_packet.bytes);
return o_packet.bytes;
}
static int encode_close(AVCodecContext* avc_context)
{
ogg_packet o_packet;
TheoraContext *h = avc_context->priv_data;
int result;
const char* message;
result = theora_encode_packetout( &(h->t_state), 1, &o_packet );
theora_clear( &(h->t_state) );
switch (result) {
case 0:/* No packet is ready */
case -1:/* Encoding finished */
return 0;
case 1:
/* We have a packet */
message = "gave us a packet";
break;
default:
message = "unknown reason";
break;
}
av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed (%s) [%d]\n", message, result);
return -1;
}
static const enum PixelFormat supported_pixel_formats[] = { PIX_FMT_YUV420P, -1 };
/*! AVCodec struct exposed to libavcodec */
AVCodec libtheora_encoder =
{
.name = "libtheora",
.type = CODEC_TYPE_VIDEO,
.id = CODEC_ID_THEORA,
.priv_data_size = sizeof(TheoraContext),
.init = encode_init,
.close = encode_close,
.encode = encode_frame,
.pix_fmts = supported_pixel_formats,
};