LCOV - code coverage report
Current view: top level - libavformat - yop.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 83 107 77.6 %
Date: 2017-12-14 01:15:32 Functions: 4 5 80.0 %

          Line data    Source code
       1             : /*
       2             :  * Psygnosis YOP demuxer
       3             :  *
       4             :  * Copyright (C) 2010 Mohamed Naufal Basheer <naufal11@gmail.com>
       5             :  * derived from the code by
       6             :  * Copyright (C) 2009 Thomas P. Higdon <thomas.p.higdon@gmail.com>
       7             :  *
       8             :  * This file is part of FFmpeg.
       9             :  *
      10             :  * FFmpeg is free software; you can redistribute it and/or
      11             :  * modify it under the terms of the GNU Lesser General Public
      12             :  * License as published by the Free Software Foundation; either
      13             :  * version 2.1 of the License, or (at your option) any later version.
      14             :  *
      15             :  * FFmpeg is distributed in the hope that it will be useful,
      16             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      17             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      18             :  * Lesser General Public License for more details.
      19             :  *
      20             :  * You should have received a copy of the GNU Lesser General Public
      21             :  * License along with FFmpeg; if not, write to the Free Software
      22             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      23             :  */
      24             : 
      25             : #include "libavutil/channel_layout.h"
      26             : #include "libavutil/intreadwrite.h"
      27             : #include "avformat.h"
      28             : #include "internal.h"
      29             : 
      30             : typedef struct yop_dec_context {
      31             :     AVPacket video_packet;
      32             : 
      33             :     int odd_frame;
      34             :     int frame_size;
      35             :     int audio_block_length;
      36             :     int palette_size;
      37             : } YopDecContext;
      38             : 
      39        6130 : static int yop_probe(AVProbeData *probe_packet)
      40             : {
      41        6131 :     if (AV_RB16(probe_packet->buf) == AV_RB16("YO")  &&
      42           2 :         probe_packet->buf[2]<10                      &&
      43           2 :         probe_packet->buf[3]<10                      &&
      44           2 :         probe_packet->buf[6]                         &&
      45           2 :         probe_packet->buf[7]                         &&
      46           2 :         !(probe_packet->buf[8] & 1)                  &&
      47           2 :         !(probe_packet->buf[10] & 1)                 &&
      48           2 :         AV_RL16(probe_packet->buf + 12 + 6) >= 920    &&
      49           1 :         AV_RL16(probe_packet->buf + 12 + 6) < probe_packet->buf[12] * 3 + 4 + probe_packet->buf[7] * 2048
      50             :     )
      51           1 :         return AVPROBE_SCORE_MAX * 3 / 4;
      52             : 
      53        6129 :     return 0;
      54             : }
      55             : 
      56           1 : static int yop_read_header(AVFormatContext *s)
      57             : {
      58           1 :     YopDecContext *yop = s->priv_data;
      59           1 :     AVIOContext *pb  = s->pb;
      60             : 
      61             :     AVCodecParameters *audio_par, *video_par;
      62             :     AVStream *audio_stream, *video_stream;
      63             : 
      64             :     int frame_rate, ret;
      65             : 
      66           1 :     audio_stream = avformat_new_stream(s, NULL);
      67           1 :     video_stream = avformat_new_stream(s, NULL);
      68           1 :     if (!audio_stream || !video_stream)
      69           0 :         return AVERROR(ENOMEM);
      70             : 
      71             :     // Extra data that will be passed to the decoder
      72           1 :     if (ff_alloc_extradata(video_stream->codecpar, 8))
      73           0 :         return AVERROR(ENOMEM);
      74             : 
      75             :     // Audio
      76           1 :     audio_par                 = audio_stream->codecpar;
      77           1 :     audio_par->codec_type     = AVMEDIA_TYPE_AUDIO;
      78           1 :     audio_par->codec_id       = AV_CODEC_ID_ADPCM_IMA_APC;
      79           1 :     audio_par->channels       = 1;
      80           1 :     audio_par->channel_layout = AV_CH_LAYOUT_MONO;
      81           1 :     audio_par->sample_rate    = 22050;
      82             : 
      83             :     // Video
      84           1 :     video_par               = video_stream->codecpar;
      85           1 :     video_par->codec_type   = AVMEDIA_TYPE_VIDEO;
      86           1 :     video_par->codec_id     = AV_CODEC_ID_YOP;
      87             : 
      88           1 :     avio_skip(pb, 6);
      89             : 
      90           1 :     frame_rate              = avio_r8(pb);
      91           1 :     yop->frame_size         = avio_r8(pb) * 2048;
      92           1 :     video_par->width        = avio_rl16(pb);
      93           1 :     video_par->height       = avio_rl16(pb);
      94             : 
      95           1 :     video_stream->sample_aspect_ratio = (AVRational){1, 2};
      96             : 
      97           1 :     ret = avio_read(pb, video_par->extradata, 8);
      98           1 :     if (ret < 8)
      99           0 :         return ret < 0 ? ret : AVERROR_EOF;
     100             : 
     101           1 :     yop->palette_size       = video_par->extradata[0] * 3 + 4;
     102           1 :     yop->audio_block_length = AV_RL16(video_par->extradata + 6);
     103             : 
     104           1 :     video_par->bit_rate     = 8 * (yop->frame_size - yop->audio_block_length) * frame_rate;
     105             : 
     106             :     // 1840 samples per frame, 1 nibble per sample; hence 1840/2 = 920
     107           2 :     if (yop->audio_block_length < 920 ||
     108           1 :         yop->audio_block_length + yop->palette_size >= yop->frame_size) {
     109           0 :         av_log(s, AV_LOG_ERROR, "YOP has invalid header\n");
     110           0 :         return AVERROR_INVALIDDATA;
     111             :     }
     112             : 
     113           1 :     avio_seek(pb, 2048, SEEK_SET);
     114             : 
     115           1 :     avpriv_set_pts_info(video_stream, 32, 1, frame_rate);
     116             : 
     117           1 :     return 0;
     118             : }
     119             : 
     120          16 : static int yop_read_packet(AVFormatContext *s, AVPacket *pkt)
     121             : {
     122          16 :     YopDecContext *yop = s->priv_data;
     123          16 :     AVIOContext *pb  = s->pb;
     124             : 
     125             :     int ret;
     126          48 :     int actual_video_data_size = yop->frame_size -
     127          32 :                                  yop->audio_block_length - yop->palette_size;
     128             : 
     129          16 :     yop->video_packet.stream_index = 1;
     130             : 
     131          16 :     if (yop->video_packet.data) {
     132           7 :         *pkt                   =  yop->video_packet;
     133           7 :         yop->video_packet.data =  NULL;
     134           7 :         yop->video_packet.buf  =  NULL;
     135           7 :         yop->video_packet.size =  0;
     136           7 :         pkt->data[0]           =  yop->odd_frame;
     137           7 :         pkt->flags             |= AV_PKT_FLAG_KEY;
     138           7 :         yop->odd_frame         ^= 1;
     139           7 :         return pkt->size;
     140             :     }
     141           9 :     ret = av_new_packet(&yop->video_packet,
     142           9 :                         yop->frame_size - yop->audio_block_length);
     143           9 :     if (ret < 0)
     144           0 :         return ret;
     145             : 
     146           9 :     yop->video_packet.pos = avio_tell(pb);
     147             : 
     148           9 :     ret = avio_read(pb, yop->video_packet.data, yop->palette_size);
     149           9 :     if (ret < 0) {
     150           2 :         goto err_out;
     151           7 :     }else if (ret < yop->palette_size) {
     152           0 :         ret = AVERROR_EOF;
     153           0 :         goto err_out;
     154             :     }
     155             : 
     156           7 :     ret = av_get_packet(pb, pkt, 920);
     157           7 :     if (ret < 0)
     158           0 :         goto err_out;
     159             : 
     160             :     // Set position to the start of the frame
     161           7 :     pkt->pos = yop->video_packet.pos;
     162             : 
     163           7 :     avio_skip(pb, yop->audio_block_length - ret);
     164             : 
     165           7 :     ret = avio_read(pb, yop->video_packet.data + yop->palette_size,
     166             :                      actual_video_data_size);
     167           7 :     if (ret < 0)
     168           0 :         goto err_out;
     169           7 :     else if (ret < actual_video_data_size)
     170           1 :         av_shrink_packet(&yop->video_packet, yop->palette_size + ret);
     171             : 
     172             :     // Arbitrarily return the audio data first
     173           7 :     return yop->audio_block_length;
     174             : 
     175           2 : err_out:
     176           2 :     av_packet_unref(&yop->video_packet);
     177           2 :     return ret;
     178             : }
     179             : 
     180           1 : static int yop_read_close(AVFormatContext *s)
     181             : {
     182           1 :     YopDecContext *yop = s->priv_data;
     183           1 :     av_packet_unref(&yop->video_packet);
     184           1 :     return 0;
     185             : }
     186             : 
     187           0 : static int yop_read_seek(AVFormatContext *s, int stream_index,
     188             :                          int64_t timestamp, int flags)
     189             : {
     190           0 :     YopDecContext *yop = s->priv_data;
     191             :     int64_t frame_pos, pos_min, pos_max;
     192             :     int frame_count;
     193             : 
     194           0 :     if (!stream_index)
     195           0 :         return -1;
     196             : 
     197           0 :     pos_min        = s->internal->data_offset;
     198           0 :     pos_max        = avio_size(s->pb) - yop->frame_size;
     199           0 :     frame_count    = (pos_max - pos_min) / yop->frame_size;
     200             : 
     201           0 :     timestamp      = FFMAX(0, FFMIN(frame_count, timestamp));
     202             : 
     203           0 :     frame_pos      = timestamp * yop->frame_size + pos_min;
     204             : 
     205           0 :     if (avio_seek(s->pb, frame_pos, SEEK_SET) < 0)
     206           0 :         return -1;
     207             : 
     208           0 :     av_packet_unref(&yop->video_packet);
     209           0 :     yop->odd_frame = timestamp & 1;
     210             : 
     211           0 :     return 0;
     212             : }
     213             : 
     214             : AVInputFormat ff_yop_demuxer = {
     215             :     .name           = "yop",
     216             :     .long_name      = NULL_IF_CONFIG_SMALL("Psygnosis YOP"),
     217             :     .priv_data_size = sizeof(YopDecContext),
     218             :     .read_probe     = yop_probe,
     219             :     .read_header    = yop_read_header,
     220             :     .read_packet    = yop_read_packet,
     221             :     .read_close     = yop_read_close,
     222             :     .read_seek      = yop_read_seek,
     223             :     .extensions     = "yop",
     224             :     .flags          = AVFMT_GENERIC_INDEX,
     225             : };

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