PeerStreamer

/*

 * ARMovie/RPL demuxer

 * Copyright (c) 2007 Christian Ohm, 2008 Eli Friedman

 *

 * 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

 */

#include "libavutil/avstring.h"

#include "avformat.h"

#include <stdlib.h>

#define RPL_SIGNATURE "ARMovie\x0A"

#define RPL_SIGNATURE_SIZE 8

/** 256 is arbitrary, but should be big enough for any reasonable file. */

#define RPL_LINE_LENGTH 256

static int rpl_probe(AVProbeData *p)

{

    if (memcmp(p->buf, RPL_SIGNATURE, RPL_SIGNATURE_SIZE))

        return 0;

    return AVPROBE_SCORE_MAX;

}

typedef struct RPLContext {

    // RPL header data

    int32_t frames_per_chunk;

    // Stream position data

    uint32_t chunk_number;

    uint32_t chunk_part;

    uint32_t frame_in_part;

} RPLContext;

static int read_line(ByteIOContext * pb, char* line, int bufsize)

{

    int i;

    for (i = 0; i < bufsize - 1; i++) {

        int b = get_byte(pb);

        if (b == 0)

            break;

        if (b == '\n') {

            line[i] = '\0';

            return 0;

        }

        line[i] = b;

    }

    line[i] = '\0';

    return -1;

}

static int32_t read_int(const char* line, const char** endptr, int* error)

{

    unsigned long result = 0;

    for (; *line>='0' && *line<='9'; line++) {

        if (result > (0x7FFFFFFF - 9) / 10)

            *error = -1;

        result = 10 * result + *line - '0';

    }

    *endptr = line;

    return result;

}

static int32_t read_line_and_int(ByteIOContext * pb, int* error)

{

    char line[RPL_LINE_LENGTH];

    const char *endptr;

    *error |= read_line(pb, line, sizeof(line));

    return read_int(line, &endptr, error);

}

/** Parsing for fps, which can be a fraction. Unfortunately,

  * the spec for the header leaves out a lot of details,

  * so this is mostly guessing.

  */

static AVRational read_fps(const char* line, int* error)

{

    int64_t num, den = 1;

    AVRational result;

    num = read_int(line, &line, error);

    if (*line == '.')

        line++;

    for (; *line>='0' && *line<='9'; line++) {

        // Truncate any numerator too large to fit into an int64_t

        if (num > (INT64_MAX - 9) / 10 || den > INT64_MAX / 10)

            break;

        num  = 10 * num + *line - '0';

        den *= 10;

    }

    if (!num)

        *error = -1;

    av_reduce(&result.num, &result.den, num, den, 0x7FFFFFFF);

    return result;

}

static int rpl_read_header(AVFormatContext *s, AVFormatParameters *ap)

{

    ByteIOContext *pb = s->pb;

    RPLContext *rpl = s->priv_data;

    AVStream *vst = NULL, *ast = NULL;

    int total_audio_size;

    int error = 0;

    uint32_t i;

    int32_t audio_format, chunk_catalog_offset, number_of_chunks;

    AVRational fps;

    char line[RPL_LINE_LENGTH];

    // The header for RPL/ARMovie files is 21 lines of text

    // containing the various header fields.  The fields are always

    // in the same order, and other text besides the first

    // number usually isn't important.

    // (The spec says that there exists some significance

    // for the text in a few cases; samples needed.)

    error |= read_line(pb, line, sizeof(line));      // ARMovie

    error |= read_line(pb, line, sizeof(line));      // movie name

    av_metadata_set(&s->metadata, "title"    , line);

    error |= read_line(pb, line, sizeof(line));      // date/copyright

    av_metadata_set(&s->metadata, "copyright", line);

    error |= read_line(pb, line, sizeof(line));      // author and other

    av_metadata_set(&s->metadata, "author"   , line);

    // video headers

    vst = av_new_stream(s, 0);

    if (!vst)

        return AVERROR(ENOMEM);

    vst->codec->codec_type      = AVMEDIA_TYPE_VIDEO;

    vst->codec->codec_tag       = read_line_and_int(pb, &error);  // video format

    vst->codec->width           = read_line_and_int(pb, &error);  // video width

    vst->codec->height          = read_line_and_int(pb, &error);  // video height

    vst->codec->bits_per_coded_sample = read_line_and_int(pb, &error);  // video bits per sample

    error |= read_line(pb, line, sizeof(line));                   // video frames per second

    fps = read_fps(line, &error);

    av_set_pts_info(vst, 32, fps.den, fps.num);

    // Figure out the video codec

    switch (vst->codec->codec_tag) {

#if 0

        case 122:

            vst->codec->codec_id = CODEC_ID_ESCAPE122;

            break;

#endif

        case 124:

            vst->codec->codec_id = CODEC_ID_ESCAPE124;

            // The header is wrong here, at least sometimes

            vst->codec->bits_per_coded_sample = 16;

            break;

#if 0

        case 130:

            vst->codec->codec_id = CODEC_ID_ESCAPE130;

            break;

#endif

        default:

            av_log(s, AV_LOG_WARNING,

                   "RPL video format %i not supported yet!\n",

                   vst->codec->codec_tag);

            vst->codec->codec_id = CODEC_ID_NONE;

    }

    // Audio headers

    // ARMovie supports multiple audio tracks; I don't have any

    // samples, though. This code will ignore additional tracks.

    audio_format = read_line_and_int(pb, &error);  // audio format ID

    if (audio_format) {

        ast = av_new_stream(s, 0);

        if (!ast)

            return AVERROR(ENOMEM);

        ast->codec->codec_type      = AVMEDIA_TYPE_AUDIO;

        ast->codec->codec_tag       = audio_format;

        ast->codec->sample_rate     = read_line_and_int(pb, &error);  // audio bitrate

        ast->codec->channels        = read_line_and_int(pb, &error);  // number of audio channels

        ast->codec->bits_per_coded_sample = read_line_and_int(pb, &error);  // audio bits per sample

        // At least one sample uses 0 for ADPCM, which is really 4 bits

        // per sample.

        if (ast->codec->bits_per_coded_sample == 0)

            ast->codec->bits_per_coded_sample = 4;

        ast->codec->bit_rate = ast->codec->sample_rate *

                               ast->codec->bits_per_coded_sample *

                               ast->codec->channels;

        ast->codec->codec_id = CODEC_ID_NONE;

        switch (audio_format) {

            case 1:

                if (ast->codec->bits_per_coded_sample == 16) {

                    // 16-bit audio is always signed

                    ast->codec->codec_id = CODEC_ID_PCM_S16LE;

                    break;

                }

                // There are some other formats listed as legal per the spec;

                // samples needed.

                break;

            case 101:

                if (ast->codec->bits_per_coded_sample == 8) {

                    // The samples with this kind of audio that I have

                    // are all unsigned.

                    ast->codec->codec_id = CODEC_ID_PCM_U8;

                    break;

                } else if (ast->codec->bits_per_coded_sample == 4) {

                    ast->codec->codec_id = CODEC_ID_ADPCM_IMA_EA_SEAD;

                    break;

                }

                break;

        }

        if (ast->codec->codec_id == CODEC_ID_NONE) {

            av_log(s, AV_LOG_WARNING,

                   "RPL audio format %i not supported yet!\n",

                   audio_format);

        }

        av_set_pts_info(ast, 32, 1, ast->codec->bit_rate);

    } else {

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

            error |= read_line(pb, line, sizeof(line));

    }

    rpl->frames_per_chunk = read_line_and_int(pb, &error);  // video frames per chunk

    if (rpl->frames_per_chunk > 1 && vst->codec->codec_tag != 124)

        av_log(s, AV_LOG_WARNING,

               "Don't know how to split frames for video format %i. "

               "Video stream will be broken!\n", vst->codec->codec_tag);

    number_of_chunks = read_line_and_int(pb, &error);  // number of chunks in the file

    // The number in the header is actually the index of the last chunk.

    number_of_chunks++;

    error |= read_line(pb, line, sizeof(line));  // "even" chunk size in bytes

    error |= read_line(pb, line, sizeof(line));  // "odd" chunk size in bytes

    chunk_catalog_offset =                       // offset of the "chunk catalog"

        read_line_and_int(pb, &error);           //   (file index)

    error |= read_line(pb, line, sizeof(line));  // offset to "helpful" sprite

    error |= read_line(pb, line, sizeof(line));  // size of "helpful" sprite

    error |= read_line(pb, line, sizeof(line));  // offset to key frame list

    // Read the index

    url_fseek(pb, chunk_catalog_offset, SEEK_SET);

    total_audio_size = 0;

    for (i = 0; i < number_of_chunks; i++) {

        int64_t offset, video_size, audio_size;

        error |= read_line(pb, line, sizeof(line));

        if (3 != sscanf(line, "%"PRId64" , %"PRId64" ; %"PRId64,

                        &offset, &video_size, &audio_size))

            error = -1;

        av_add_index_entry(vst, offset, i * rpl->frames_per_chunk,

                           video_size, rpl->frames_per_chunk, 0);

        if (ast)

            av_add_index_entry(ast, offset + video_size, total_audio_size,

                               audio_size, audio_size * 8, 0);

        total_audio_size += audio_size * 8;

    }

    if (error) return AVERROR(EIO);

    return 0;

}

static int rpl_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    RPLContext *rpl = s->priv_data;

    ByteIOContext *pb = s->pb;

    AVStream* stream;

    AVIndexEntry* index_entry;

    uint32_t ret;

    if (rpl->chunk_part == s->nb_streams) {

        rpl->chunk_number++;

        rpl->chunk_part = 0;

    }

    stream = s->streams[rpl->chunk_part];

    if (rpl->chunk_number >= stream->nb_index_entries)

        return -1;

    index_entry = &stream->index_entries[rpl->chunk_number];

    if (rpl->frame_in_part == 0)

        if (url_fseek(pb, index_entry->pos, SEEK_SET) < 0)

            return AVERROR(EIO);

    if (stream->codec->codec_type == AVMEDIA_TYPE_VIDEO &&

        stream->codec->codec_tag == 124) {

        // We have to split Escape 124 frames because there are

        // multiple frames per chunk in Escape 124 samples.

        uint32_t frame_size, frame_flags;

        frame_flags = get_le32(pb);

        frame_size = get_le32(pb);

        if (url_fseek(pb, -8, SEEK_CUR) < 0)

            return AVERROR(EIO);

        ret = av_get_packet(pb, pkt, frame_size);

        if (ret != frame_size) {

            av_free_packet(pkt);

            return AVERROR(EIO);

        }

        pkt->duration = 1;

        pkt->pts = index_entry->timestamp + rpl->frame_in_part;

        pkt->stream_index = rpl->chunk_part;

        rpl->frame_in_part++;

        if (rpl->frame_in_part == rpl->frames_per_chunk) {

            rpl->frame_in_part = 0;

            rpl->chunk_part++;

        }

    } else {

        ret = av_get_packet(pb, pkt, index_entry->size);

        if (ret != index_entry->size) {

            av_free_packet(pkt);

            return AVERROR(EIO);

        }

        if (stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

            // frames_per_chunk should always be one here; the header

            // parsing will warn if it isn't.

            pkt->duration = rpl->frames_per_chunk;

        } else {

            // All the audio codecs supported in this container

            // (at least so far) are constant-bitrate.

            pkt->duration = ret * 8;

        }

        pkt->pts = index_entry->timestamp;

        pkt->stream_index = rpl->chunk_part;

        rpl->chunk_part++;

    }

    // None of the Escape formats have keyframes, and the ADPCM

    // format used doesn't have keyframes.

    if (rpl->chunk_number == 0 && rpl->frame_in_part == 0)

        pkt->flags |= PKT_FLAG_KEY;

    return ret;

}

AVInputFormat rpl_demuxer = {

    "rpl",

    NULL_IF_CONFIG_SMALL("RPL/ARMovie format"),

    sizeof(RPLContext),

    rpl_probe,

    rpl_read_header,

    rpl_read_packet,

};