| /* |
| * a64 muxer |
| * Copyright (c) 2009 Tobias Bindhammer |
| * |
| * 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 "libavcodec/avcodec.h" |
| #include "libavcodec/a64enc.h" |
| #include "libavcodec/bytestream.h" |
| #include "avformat.h" |
| |
| typedef struct A64MuxerContext { |
| int interleaved; |
| AVPacket prev_pkt; |
| int prev_frame_count; |
| } A64MuxerContext; |
| |
| static int a64_write_header(struct AVFormatContext *s) |
| { |
| AVCodecContext *avctx = s->streams[0]->codec; |
| A64MuxerContext *c = s->priv_data; |
| uint8_t header[5] = { |
| 0x00, //load |
| 0x40, //address |
| 0x00, //mode |
| 0x00, //charset_lifetime (multi only) |
| 0x00 //fps in 50/fps; |
| }; |
| c->interleaved = 0; |
| switch (avctx->codec->id) { |
| case CODEC_ID_A64_MULTI: |
| header[2] = 0x00; |
| header[3] = AV_RB32(avctx->extradata+0); |
| header[4] = 2; |
| break; |
| case CODEC_ID_A64_MULTI5: |
| header[2] = 0x01; |
| header[3] = AV_RB32(avctx->extradata+0); |
| header[4] = 3; |
| break; |
| default: |
| return AVERROR(EINVAL); |
| break; |
| } |
| avio_write(s->pb, header, 2); |
| c->prev_pkt.size = 0; |
| c->prev_frame_count = 0; |
| return 0; |
| } |
| |
| static int a64_write_packet(struct AVFormatContext *s, AVPacket *pkt) |
| { |
| AVCodecContext *avctx = s->streams[0]->codec; |
| A64MuxerContext *c = s->priv_data; |
| int i, j; |
| int ch_chunksize; |
| int lifetime; |
| int frame_count; |
| int charset_size; |
| int frame_size; |
| int num_frames; |
| |
| /* fetch values from extradata */ |
| switch (avctx->codec->id) { |
| case CODEC_ID_A64_MULTI: |
| case CODEC_ID_A64_MULTI5: |
| if(c->interleaved) { |
| /* Write interleaved, means we insert chunks of the future charset before each current frame. |
| * Reason: if we load 1 charset + corresponding frames in one block on c64, we need to store |
| * them first and then display frame by frame to keep in sync. Thus we would read and write |
| * the data for colram from/to ram first and waste too much time. If we interleave and send the |
| * charset beforehand, we assemble a new charset chunk by chunk, write current screen data to |
| * screen-ram to be displayed and decode the colram directly to colram-location $d800 during |
| * the overscan, while reading directly from source. |
| * This is the only way so far, to achieve 25fps on c64 */ |
| if(avctx->extradata) { |
| /* fetch values from extradata */ |
| lifetime = AV_RB32(avctx->extradata + 0); |
| frame_count = AV_RB32(avctx->extradata + 4); |
| charset_size = AV_RB32(avctx->extradata + 8); |
| frame_size = AV_RB32(avctx->extradata + 12); |
| |
| /* TODO: sanity checks? */ |
| } else { |
| av_log(avctx, AV_LOG_ERROR, "extradata not set\n"); |
| return AVERROR(EINVAL); |
| } |
| |
| ch_chunksize=charset_size/lifetime; |
| /* TODO: check if charset/size is % lifetime, but maybe check in codec */ |
| |
| if(pkt->data) num_frames = lifetime; |
| else num_frames = c->prev_frame_count; |
| |
| for(i = 0; i < num_frames; i++) { |
| if(pkt->data) { |
| /* if available, put newest charset chunk into buffer */ |
| avio_write(s->pb, pkt->data + ch_chunksize * i, ch_chunksize); |
| } else { |
| /* a bit ugly, but is there an alternative to put many zeros? */ |
| for(j = 0; j < ch_chunksize; j++) avio_w8(s->pb, 0); |
| } |
| |
| if(c->prev_pkt.data) { |
| /* put frame (screen + colram) from last packet into buffer */ |
| avio_write(s->pb, c->prev_pkt.data + charset_size + frame_size * i, frame_size); |
| } else { |
| /* a bit ugly, but is there an alternative to put many zeros? */ |
| for(j = 0; j < frame_size; j++) avio_w8(s->pb, 0); |
| } |
| } |
| |
| /* backup current packet for next turn */ |
| if(pkt->data) { |
| /* no backup packet yet? create one! */ |
| if(!c->prev_pkt.data) av_new_packet(&c->prev_pkt, pkt->size); |
| /* we have a packet and data is big enough, reuse it */ |
| if(c->prev_pkt.data && c->prev_pkt.size >= pkt->size) { |
| memcpy(c->prev_pkt.data, pkt->data, pkt->size); |
| c->prev_pkt.size = pkt->size; |
| } else { |
| av_log(avctx, AV_LOG_ERROR, "Too less memory for prev_pkt.\n"); |
| return AVERROR(ENOMEM); |
| } |
| } |
| |
| c->prev_frame_count = frame_count; |
| break; |
| } |
| default: |
| /* Write things as is. Nice for self-contained frames from non-multicolor modes or if played |
| * directly from ram and not from a streaming device (rrnet/mmc) */ |
| if(pkt) avio_write(s->pb, pkt->data, pkt->size); |
| break; |
| } |
| |
| avio_flush(s->pb); |
| return 0; |
| } |
| |
| static int a64_write_trailer(struct AVFormatContext *s) |
| { |
| A64MuxerContext *c = s->priv_data; |
| AVPacket pkt = {0}; |
| /* need to flush last packet? */ |
| if(c->interleaved) a64_write_packet(s, &pkt); |
| /* discard backed up packet */ |
| if(c->prev_pkt.data) av_destruct_packet(&c->prev_pkt); |
| return 0; |
| } |
| |
| AVOutputFormat ff_a64_muxer = { |
| .name = "a64", |
| .long_name = NULL_IF_CONFIG_SMALL("a64 - video for Commodore 64"), |
| .mime_type = NULL, |
| .extensions = "a64, A64", |
| .priv_data_size = sizeof (A64Context), |
| .video_codec = CODEC_ID_A64_MULTI, |
| a64_write_header, |
| a64_write_packet, |
| a64_write_trailer |
| }; |