diff options
Diffstat (limited to 'contrib/ffmpeg/libavformat/idcin.c')
| -rw-r--r-- | contrib/ffmpeg/libavformat/idcin.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavformat/idcin.c b/contrib/ffmpeg/libavformat/idcin.c new file mode 100644 index 000000000..e2c92f3b4 --- /dev/null +++ b/contrib/ffmpeg/libavformat/idcin.c @@ -0,0 +1,301 @@ +/* + * Id Quake II CIN File Demuxer + * Copyright (c) 2003 The ffmpeg Project + * + * 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 idcin.c + * Id Quake II CIN file demuxer by Mike Melanson (melanson@pcisys.net) + * For more information about the Id CIN format, visit: + * http://www.csse.monash.edu.au/~timf/ + * + * CIN is a somewhat quirky and ill-defined format. Here are some notes + * for anyone trying to understand the technical details of this format: + * + * The format has no definite file signature. This is problematic for a + * general-purpose media player that wants to automatically detect file + * types. However, a CIN file does start with 5 32-bit numbers that + * specify audio and video parameters. This demuxer gets around the lack + * of file signature by performing sanity checks on those parameters. + * Probabalistically, this is a reasonable solution since the number of + * valid combinations of the 5 parameters is a very small subset of the + * total 160-bit number space. + * + * Refer to the function idcin_probe() for the precise A/V parameters + * that this demuxer allows. + * + * Next, each audio and video frame has a duration of 1/14 sec. If the + * audio sample rate is a multiple of the common frequency 22050 Hz it will + * divide evenly by 14. However, if the sample rate is 11025 Hz: + * 11025 (samples/sec) / 14 (frames/sec) = 787.5 (samples/frame) + * The way the CIN stores audio in this case is by storing 787 sample + * frames in the first audio frame and 788 sample frames in the second + * audio frame. Therefore, the total number of bytes in an audio frame + * is given as: + * audio frame #0: 787 * (bytes/sample) * (# channels) bytes in frame + * audio frame #1: 788 * (bytes/sample) * (# channels) bytes in frame + * audio frame #2: 787 * (bytes/sample) * (# channels) bytes in frame + * audio frame #3: 788 * (bytes/sample) * (# channels) bytes in frame + * + * Finally, not all Id CIN creation tools agree on the resolution of the + * color palette, apparently. Some creation tools specify red, green, and + * blue palette components in terms of 6-bit VGA color DAC values which + * range from 0..63. Other tools specify the RGB components as full 8-bit + * values that range from 0..255. Since there are no markers in the file to + * differentiate between the two variants, this demuxer uses the following + * heuristic: + * - load the 768 palette bytes from disk + * - assume that they will need to be shifted left by 2 bits to + * transform them from 6-bit values to 8-bit values + * - scan through all 768 palette bytes + * - if any bytes exceed 63, do not shift the bytes at all before + * transmitting them to the video decoder + */ + +#include "avformat.h" + +#define HUFFMAN_TABLE_SIZE (64 * 1024) +#define FRAME_PTS_INC (90000 / 14) + +typedef struct IdcinDemuxContext { + int video_stream_index; + int audio_stream_index; + int audio_chunk_size1; + int audio_chunk_size2; + + /* demux state variables */ + int current_audio_chunk; + int next_chunk_is_video; + int audio_present; + + int64_t pts; + + AVPaletteControl palctrl; +} IdcinDemuxContext; + +static int idcin_probe(AVProbeData *p) +{ + unsigned int number; + + /* + * This is what you could call a "probabilistic" file check: Id CIN + * files don't have a definite file signature. In lieu of such a marker, + * perform sanity checks on the 5 32-bit header fields: + * width, height: greater than 0, less than or equal to 1024 + * audio sample rate: greater than or equal to 8000, less than or + * equal to 48000, or 0 for no audio + * audio sample width (bytes/sample): 0 for no audio, or 1 or 2 + * audio channels: 0 for no audio, or 1 or 2 + */ + + /* cannot proceed without 20 bytes */ + if (p->buf_size < 20) + return 0; + + /* check the video width */ + number = AV_RL32(&p->buf[0]); + if ((number == 0) || (number > 1024)) + return 0; + + /* check the video height */ + number = AV_RL32(&p->buf[4]); + if ((number == 0) || (number > 1024)) + return 0; + + /* check the audio sample rate */ + number = AV_RL32(&p->buf[8]); + if ((number != 0) && ((number < 8000) | (number > 48000))) + return 0; + + /* check the audio bytes/sample */ + number = AV_RL32(&p->buf[12]); + if (number > 2) + return 0; + + /* check the audio channels */ + number = AV_RL32(&p->buf[16]); + if (number > 2) + return 0; + + /* return half certainly since this check is a bit sketchy */ + return AVPROBE_SCORE_MAX / 2; +} + +static int idcin_read_header(AVFormatContext *s, + AVFormatParameters *ap) +{ + ByteIOContext *pb = &s->pb; + IdcinDemuxContext *idcin = (IdcinDemuxContext *)s->priv_data; + AVStream *st; + unsigned int width, height; + unsigned int sample_rate, bytes_per_sample, channels; + + /* get the 5 header parameters */ + width = get_le32(pb); + height = get_le32(pb); + sample_rate = get_le32(pb); + bytes_per_sample = get_le32(pb); + channels = get_le32(pb); + + st = av_new_stream(s, 0); + if (!st) + return AVERROR_NOMEM; + av_set_pts_info(st, 33, 1, 90000); + idcin->video_stream_index = st->index; + st->codec->codec_type = CODEC_TYPE_VIDEO; + st->codec->codec_id = CODEC_ID_IDCIN; + st->codec->codec_tag = 0; /* no fourcc */ + st->codec->width = width; + st->codec->height = height; + + /* load up the Huffman tables into extradata */ + st->codec->extradata_size = HUFFMAN_TABLE_SIZE; + st->codec->extradata = av_malloc(HUFFMAN_TABLE_SIZE); + if (get_buffer(pb, st->codec->extradata, HUFFMAN_TABLE_SIZE) != + HUFFMAN_TABLE_SIZE) + return AVERROR_IO; + /* save a reference in order to transport the palette */ + st->codec->palctrl = &idcin->palctrl; + + /* if sample rate is 0, assume no audio */ + if (sample_rate) { + idcin->audio_present = 1; + st = av_new_stream(s, 0); + if (!st) + return AVERROR_NOMEM; + av_set_pts_info(st, 33, 1, 90000); + idcin->audio_stream_index = st->index; + st->codec->codec_type = CODEC_TYPE_AUDIO; + st->codec->codec_tag = 1; + st->codec->channels = channels; + st->codec->sample_rate = sample_rate; + st->codec->bits_per_sample = bytes_per_sample * 8; + st->codec->bit_rate = sample_rate * bytes_per_sample * 8 * channels; + st->codec->block_align = bytes_per_sample * channels; + if (bytes_per_sample == 1) + st->codec->codec_id = CODEC_ID_PCM_U8; + else + st->codec->codec_id = CODEC_ID_PCM_S16LE; + + if (sample_rate % 14 != 0) { + idcin->audio_chunk_size1 = (sample_rate / 14) * + bytes_per_sample * channels; + idcin->audio_chunk_size2 = (sample_rate / 14 + 1) * + bytes_per_sample * channels; + } else { + idcin->audio_chunk_size1 = idcin->audio_chunk_size2 = + (sample_rate / 14) * bytes_per_sample * channels; + } + idcin->current_audio_chunk = 0; + } else + idcin->audio_present = 1; + + idcin->next_chunk_is_video = 1; + idcin->pts = 0; + + return 0; +} + +static int idcin_read_packet(AVFormatContext *s, + AVPacket *pkt) +{ + int ret; + unsigned int command; + unsigned int chunk_size; + IdcinDemuxContext *idcin = (IdcinDemuxContext *)s->priv_data; + ByteIOContext *pb = &s->pb; + int i; + int palette_scale; + unsigned char r, g, b; + unsigned char palette_buffer[768]; + + if (url_feof(&s->pb)) + return AVERROR_IO; + + if (idcin->next_chunk_is_video) { + command = get_le32(pb); + if (command == 2) { + return AVERROR_IO; + } else if (command == 1) { + /* trigger a palette change */ + idcin->palctrl.palette_changed = 1; + if (get_buffer(pb, palette_buffer, 768) != 768) + return AVERROR_IO; + /* scale the palette as necessary */ + palette_scale = 2; + for (i = 0; i < 768; i++) + if (palette_buffer[i] > 63) { + palette_scale = 0; + break; + } + + for (i = 0; i < 256; i++) { + r = palette_buffer[i * 3 ] << palette_scale; + g = palette_buffer[i * 3 + 1] << palette_scale; + b = palette_buffer[i * 3 + 2] << palette_scale; + idcin->palctrl.palette[i] = (r << 16) | (g << 8) | (b); + } + } + + chunk_size = get_le32(pb); + /* skip the number of decoded bytes (always equal to width * height) */ + url_fseek(pb, 4, SEEK_CUR); + chunk_size -= 4; + ret= av_get_packet(pb, pkt, chunk_size); + if (ret != chunk_size) + return AVERROR_IO; + pkt->stream_index = idcin->video_stream_index; + pkt->pts = idcin->pts; + } else { + /* send out the audio chunk */ + if (idcin->current_audio_chunk) + chunk_size = idcin->audio_chunk_size2; + else + chunk_size = idcin->audio_chunk_size1; + ret= av_get_packet(pb, pkt, chunk_size); + if (ret != chunk_size) + return AVERROR_IO; + pkt->stream_index = idcin->audio_stream_index; + pkt->pts = idcin->pts; + + idcin->current_audio_chunk ^= 1; + idcin->pts += FRAME_PTS_INC; + } + + if (idcin->audio_present) + idcin->next_chunk_is_video ^= 1; + + return ret; +} + +static int idcin_read_close(AVFormatContext *s) +{ + + return 0; +} + +AVInputFormat idcin_demuxer = { + "idcin", + "Id CIN format", + sizeof(IdcinDemuxContext), + idcin_probe, + idcin_read_header, + idcin_read_packet, + idcin_read_close, +}; |