* a64 muxer
* Copyright (c) 2009 Tobias Bindhammer
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#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;
+ AVCodecContext *avctx = s->streams[0]->codec;
+ A64MuxerContext *c = s->priv_data;
uint8_t header[5] = {
0x00, //load
0x40, //address
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] = 4;
+ header[3] = AV_RB32(avctx->extradata+0);
header[4] = 2;
break;
case CODEC_ID_A64_MULTI5:
header[2] = 0x01;
- header[3] = 4;
+ header[3] = AV_RB32(avctx->extradata+0);
header[4] = 3;
break;
default:
return AVERROR(EINVAL);
- break;
}
- put_buffer(s->pb, header, 2);
+ 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)
{
- put_buffer(s->pb, pkt->data, pkt->size);
- put_flush_packet(s->pb);
+ 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 a64_muxer = {
- .name = "a64",
- .long_name = NULL_IF_CONFIG_SMALL("a64 - video for Commodore 64"),
- .mime_type = NULL,
- .extensions = "a64, A64",
+AVOutputFormat ff_a64_muxer = {
+ .name = "a64",
+ .long_name = NULL_IF_CONFIG_SMALL("a64 - video for Commodore 64"),
+ .extensions = "a64, A64",
.priv_data_size = sizeof (A64Context),
- .video_codec = CODEC_ID_A64_MULTI,
- a64_write_header,
- a64_write_packet,
+ .video_codec = CODEC_ID_A64_MULTI,
+ .write_header = a64_write_header,
+ .write_packet = a64_write_packet,
+ .write_trailer = a64_write_trailer,
};
projects / ffmpeg / blobdiff