FFmpeg/libavcodec/libschroedingerenc.c

/*
 * Dirac encoder support via Schroedinger libraries
 * Copyright (c) 2008 BBC, Anuradha Suraparaju <asuraparaju at gmail dot 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 libschroedingerenc.c
* Dirac encoder support via libschroedinger-1.0 libraries. More details about
* the Schroedinger project can be found at http://www.diracvideo.org/.
* The library implements Dirac Specification Version 2.2
* (http://dirac.sourceforge.net/specification.html).
*/

#undef NDEBUG
#include <assert.h>

#include <schroedinger/schro.h>
#include <schroedinger/schrodebug.h>
#include <schroedinger/schrovideoformat.h>

#include "avcodec.h"
#include "libdirac_libschro.h"
#include "libschroedinger.h"


/** libschroedinger encoder private data */
typedef struct FfmpegSchroEncoderParams
{
    /** Schroedinger video format */
    SchroVideoFormat *format;

    /** Schroedinger frame format */
    SchroFrameFormat frame_format;

    /** frame being encoded */
    AVFrame picture;

    /** frame size */
    int frame_size;

    /** Schroedinger encoder handle*/
    SchroEncoder* encoder;

    /** queue storing encoded frames */
    FfmpegDiracSchroQueue enc_frame_queue;

    /** end of sequence signalled */
    int eos_signalled;

    /** end of sequence pulled */
    int eos_pulled;
} FfmpegSchroEncoderParams;

/**
* Works out Schro-compatible chroma format.
*/
static int SetSchroChromaFormat(AVCodecContext *avccontext)
{
    int num_formats = sizeof(ffmpeg_schro_pixel_format_map) /
                      sizeof(ffmpeg_schro_pixel_format_map[0]);
    int idx;

    FfmpegSchroEncoderParams* p_schro_params = avccontext->priv_data;

    for (idx = 0; idx < num_formats; ++idx) {
        if (ffmpeg_schro_pixel_format_map[idx].ff_pix_fmt ==
                                                       avccontext->pix_fmt) {
            p_schro_params->format->chroma_format =
                            ffmpeg_schro_pixel_format_map[idx].schro_pix_fmt;
            return 0;
        }
    }

    av_log (avccontext, AV_LOG_ERROR,
            "This codec currently only supports planar YUV 4:2:0, 4:2:2"
            " and 4:4:4 formats.\n");

    return -1;
}

static int libschroedinger_encode_init(AVCodecContext *avccontext)
{
    FfmpegSchroEncoderParams* p_schro_params = avccontext->priv_data;
    SchroVideoFormatEnum preset;

    /* Initialize the libraries that libschroedinger depends on. */
    schro_init();

    /* Create an encoder object. */
    p_schro_params->encoder = schro_encoder_new();

    if (!p_schro_params->encoder) {
        av_log(avccontext, AV_LOG_ERROR,
               "Unrecoverable Error: schro_encoder_new failed. ");
        return -1;
    }

    /* Initialize the format. */
    preset = ff_get_schro_video_format_preset(avccontext);
    p_schro_params->format =
                    schro_encoder_get_video_format(p_schro_params->encoder);
    schro_video_format_set_std_video_format (p_schro_params->format, preset);
    p_schro_params->format->width = avccontext->width;
    p_schro_params->format->height = avccontext->height;

    if (SetSchroChromaFormat(avccontext) == -1)
        return -1;

    if (ff_get_schro_frame_format(p_schro_params->format->chroma_format,
                                  &p_schro_params->frame_format) == -1) {
        av_log (avccontext, AV_LOG_ERROR,
                "This codec currently supports only planar YUV 4:2:0, 4:2:2"
                " and 4:4:4 formats.\n");
        return -1;
    }

    p_schro_params->format->frame_rate_numerator   = avccontext->time_base.den;
    p_schro_params->format->frame_rate_denominator = avccontext->time_base.num;

    p_schro_params->frame_size = avpicture_get_size(avccontext->pix_fmt,
                                                    avccontext->width,
                                                    avccontext->height);

    avccontext->coded_frame = &p_schro_params->picture;

    if (avccontext->gop_size == 0){
        schro_encoder_setting_set_double (p_schro_params->encoder,
                                          "gop_structure",
                                          SCHRO_ENCODER_GOP_INTRA_ONLY);
    }
    else {
        schro_encoder_setting_set_double (p_schro_params->encoder,
                                          "gop_structure",
                                          SCHRO_ENCODER_GOP_BIREF);
        avccontext->has_b_frames = 1;
    }

    /* FIXME - Need to handle SCHRO_ENCODER_RATE_CONTROL_LOW_DELAY. */
    if (avccontext->flags & CODEC_FLAG_QSCALE) {
        if (avccontext->global_quality == 0) {
            /* lossless coding */
            schro_encoder_setting_set_double (p_schro_params->encoder,
                                          "rate_control",
                                          SCHRO_ENCODER_RATE_CONTROL_LOSSLESS);
        } else {
            int noise_threshold;
            schro_encoder_setting_set_double (p_schro_params->encoder,
                          "rate_control",
                          SCHRO_ENCODER_RATE_CONTROL_CONSTANT_NOISE_THRESHOLD);

            noise_threshold = avccontext->global_quality/FF_QP2LAMBDA;
            if (noise_threshold > 100)
                noise_threshold = 100;
            schro_encoder_setting_set_double (p_schro_params->encoder,
                                              "noise_threshold",
                                              noise_threshold);
        }
    }
    else {
        schro_encoder_setting_set_double ( p_schro_params->encoder,
                               "rate_control",
                               SCHRO_ENCODER_RATE_CONTROL_CONSTANT_BITRATE);

        schro_encoder_setting_set_double (p_schro_params->encoder,
                                          "bitrate",
                                          avccontext->bit_rate);

    }

    if (avccontext->flags & CODEC_FLAG_INTERLACED_ME) {
        /* All material can be coded as interlaced or progressive
           irrespective of the type of source material. */
        schro_encoder_setting_set_double (p_schro_params->encoder,
                                            "interlaced_coding", 1);
    }

    /* FIXME: Signal range hardcoded to 8-bit data until both libschroedinger
     * and libdirac support other bit-depth data. */
    schro_video_format_set_std_signal_range(p_schro_params->format,
                                            SCHRO_SIGNAL_RANGE_8BIT_VIDEO);


    /* Hardcode motion vector precision to quarter pixel. */
    schro_encoder_setting_set_double (p_schro_params->encoder,
                                      "mv_precision", 2);

    /* Set the encoder format. */
    schro_encoder_set_video_format(p_schro_params->encoder,
                                   p_schro_params->format);

    /* Set the debug level. */
    schro_debug_set_level (avccontext->debug);

    schro_encoder_start (p_schro_params->encoder);

    /* Initialize the encoded frame queue. */
    ff_dirac_schro_queue_init (&p_schro_params->enc_frame_queue);
    return 0 ;
}

static SchroFrame *libschroedinger_frame_from_data (AVCodecContext *avccontext,
                                                    void *in_data)
{
    FfmpegSchroEncoderParams* p_schro_params = avccontext->priv_data;
    SchroFrame *in_frame;
    /* Input line size may differ from what the codec supports. Especially
     * when transcoding from one format to another. So use avpicture_layout
     * to copy the frame. */
    in_frame = schro_frame_new_and_alloc (NULL,
                                          p_schro_params->frame_format,
                                          p_schro_params->format->width,
                                          p_schro_params->format->height);

    avpicture_layout ((AVPicture *)in_data, avccontext->pix_fmt,
                      avccontext->width, avccontext->height,
                      in_frame->components[0].data,
                      p_schro_params->frame_size);

    return in_frame;
}

static void SchroedingerFreeFrame(void *data)
{
    FfmpegDiracSchroEncodedFrame *enc_frame = data;

    av_freep (&(enc_frame->p_encbuf));
    av_free(enc_frame);
}

static int libschroedinger_encode_frame(AVCodecContext *avccontext,
                                        unsigned char *frame,
                                        int buf_size, void *data)
{
    int enc_size = 0;
    FfmpegSchroEncoderParams* p_schro_params = avccontext->priv_data;
    SchroEncoder *encoder = p_schro_params->encoder;
    struct FfmpegDiracSchroEncodedFrame* p_frame_output = NULL;
    int go = 1;
    SchroBuffer *enc_buf;
    int presentation_frame;
    int parse_code;

    if(data == NULL) {
        /* Push end of sequence if not already signalled. */
        if (!p_schro_params->eos_signalled) {
            schro_encoder_end_of_stream(encoder);
            p_schro_params->eos_signalled = 1;
        }
    } else {
        /* Allocate frame data to schro input buffer. */
        SchroFrame *in_frame = libschroedinger_frame_from_data (avccontext,
                                                                data);
        /* Load next frame. */
        schro_encoder_push_frame(encoder, in_frame);
    }

    if (p_schro_params->eos_pulled)
        go = 0;

    /* Now check to see if we have any output from the encoder. */
    while (go) {
        SchroStateEnum  state;
        state = schro_encoder_wait(encoder);
        switch (state)
        {
        case SCHRO_STATE_HAVE_BUFFER:
        case SCHRO_STATE_END_OF_STREAM:
            enc_buf = schro_encoder_pull (encoder,
                                          &presentation_frame);
            assert (enc_buf->length > 0);
            assert (enc_buf->length <= buf_size);

            /* Create output frame. */
            p_frame_output = av_mallocz(sizeof(FfmpegDiracSchroEncodedFrame));
            /* Set output data. */
            p_frame_output->size     = enc_buf->length;
            p_frame_output->p_encbuf = av_malloc(enc_buf->length);
            memcpy(p_frame_output->p_encbuf, enc_buf->data, enc_buf->length);

            parse_code = enc_buf->data[4];
            if (SCHRO_PARSE_CODE_IS_INTRA(parse_code) &&
                SCHRO_PARSE_CODE_IS_REFERENCE(parse_code)) {
                p_frame_output->key_frame = 1;
            }

            /* Parse the coded frame number from the bitstream. Bytes 14
             * through 17 represesent the frame number. */
            if (SCHRO_PARSE_CODE_IS_PICTURE(parse_code))
            {
                assert (enc_buf->length >= 17);
                p_frame_output->frame_num = (enc_buf->data[13] << 24) +
                                            (enc_buf->data[14] << 16) +
                                            (enc_buf->data[15] <<  8) +
                                             enc_buf->data[16];
            }

            ff_dirac_schro_queue_push_back (&p_schro_params->enc_frame_queue,
                                            p_frame_output);
            schro_buffer_unref (enc_buf);

            if (state == SCHRO_STATE_END_OF_STREAM) {
                p_schro_params->eos_pulled = 1;
                   go = 0;
            }
            break;

        case SCHRO_STATE_NEED_FRAME:
            go = 0;
            break;

        case SCHRO_STATE_AGAIN:
            break;

        default:
            av_log(avccontext, AV_LOG_ERROR, "Unknown Schro Encoder state\n");
            return -1;
        }
    }

    /* Copy 'next' frame in queue. */
    p_frame_output =
               ff_dirac_schro_queue_pop (&p_schro_params->enc_frame_queue);

    if (p_frame_output == NULL)
        return 0;

    memcpy(frame, p_frame_output->p_encbuf, p_frame_output->size);
    avccontext->coded_frame->key_frame = p_frame_output->key_frame;
    /* Use the frame number of the encoded frame as the pts. It is OK to
     * do so since Dirac is a constant frame rate codec. It expects input
     * to be of constant frame rate. */
    avccontext->coded_frame->pts = p_frame_output->frame_num;
    enc_size = p_frame_output->size;

    /* free frame */
    SchroedingerFreeFrame (p_frame_output);

    return enc_size;
}


static int libschroedinger_encode_close(AVCodecContext *avccontext)
{

    FfmpegSchroEncoderParams* p_schro_params = avccontext->priv_data;

     /* Close the encoder. */
    schro_encoder_free(p_schro_params->encoder);

    /* Free data in the output frame queue. */
    ff_dirac_schro_queue_free (&p_schro_params->enc_frame_queue,
                               SchroedingerFreeFrame);

    /* Free the video format structure. */
    av_freep(&p_schro_params->format);

    return 0 ;
}


AVCodec libschroedinger_encoder = {
    "libschroedinger",
    CODEC_TYPE_VIDEO,
    CODEC_ID_DIRAC,
    sizeof(FfmpegSchroEncoderParams),
    libschroedinger_encode_init,
    libschroedinger_encode_frame,
    libschroedinger_encode_close,
   .capabilities= CODEC_CAP_DELAY,
   .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUV420P, PIX_FMT_YUV422P, PIX_FMT_YUV444P, -1},
};