From 161fac3346d392403e28826009bfc99a3053fa9e Mon Sep 17 00:00:00 2001 From: Stephan Hilb Date: Thu, 23 Aug 2012 18:40:22 +0200 Subject: [PATCH] Add CPiA video decoder The cpia video decoder is intended to be used with the v4l2 demuxer. There are some small changes to the v4l2 demuxer to support the variable frame length of the format. --- doc/general.texi | 1 + libavcodec/Makefile | 1 + libavcodec/allcodecs.c | 1 + libavcodec/avcodec.h | 1 + libavcodec/codec_desc.c | 6 ++ libavcodec/cpia.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++ libavdevice/v4l2.c | 18 +++- 7 files changed, 254 insertions(+), 1 deletion(-) create mode 100644 libavcodec/cpia.c diff --git a/doc/general.texi b/doc/general.texi index 419eac7..02f449a 100644 --- a/doc/general.texi +++ b/doc/general.texi @@ -177,6 +177,7 @@ library: @tab Amiga CD video format @item Core Audio Format @tab X @tab X @tab Apple Core Audio Format +@item CPiA Video Format @tab X @tab @item CRC testing format @tab X @tab @item Creative Voice @tab X @tab X @tab Created for the Sound Blaster Pro. diff --git a/libavcodec/Makefile b/libavcodec/Makefile index c3de2cb..e9b4806 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -141,6 +141,7 @@ OBJS-$(CONFIG_CLJR_DECODER) += cljr.o OBJS-$(CONFIG_CLJR_ENCODER) += cljr.o OBJS-$(CONFIG_CLLC_DECODER) += cllc.o OBJS-$(CONFIG_COOK_DECODER) += cook.o +OBJS-$(CONFIG_CPIA_DECODER) += cpia.o OBJS-$(CONFIG_CSCD_DECODER) += cscd.o OBJS-$(CONFIG_CYUV_DECODER) += cyuv.o OBJS-$(CONFIG_DCA_DECODER) += dcadec.o dca.o dcadsp.o \ diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c index 1ddd440..d0cec39 100644 --- a/libavcodec/allcodecs.c +++ b/libavcodec/allcodecs.c @@ -97,6 +97,7 @@ void avcodec_register_all(void) REGISTER_DECODER (CINEPAK, cinepak); REGISTER_ENCDEC (CLJR, cljr); REGISTER_DECODER (CLLC, cllc); + REGISTER_DECODER (CPIA, cpia); REGISTER_DECODER (CSCD, cscd); REGISTER_DECODER (CYUV, cyuv); REGISTER_DECODER (DFA, dfa); diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h index c3cde34..40671ca 100644 --- a/libavcodec/avcodec.h +++ b/libavcodec/avcodec.h @@ -277,6 +277,7 @@ enum AVCodecID { AV_CODEC_ID_SANM = MKBETAG('S','A','N','M'), AV_CODEC_ID_PAF_VIDEO = MKBETAG('P','A','F','V'), AV_CODEC_ID_AVRN = MKBETAG('A','V','R','n'), + AV_CODEC_ID_CPIA = MKBETAG('C','P','I','A'), /* various PCM "codecs" */ AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c index dd4870d..0b619db 100644 --- a/libavcodec/codec_desc.c +++ b/libavcodec/codec_desc.c @@ -1183,6 +1183,12 @@ static const AVCodecDescriptor codec_descriptors[] = { .name = "avrn", .long_name = NULL_IF_CONFIG_SMALL("Avid AVI Codec"), }, + { + .id = AV_CODEC_ID_CPIA, + .type = AVMEDIA_TYPE_VIDEO, + .name = "cpia", + .long_name = NULL_IF_CONFIG_SMALL("CPiA video format"), + }, /* various PCM "codecs" */ { diff --git a/libavcodec/cpia.c b/libavcodec/cpia.c new file mode 100644 index 0000000..a3b3e54 --- /dev/null +++ b/libavcodec/cpia.c @@ -0,0 +1,227 @@ +/* + * CPiA video decoder. + * Copyright (c) 2012 + * + * 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 "avcodec.h" +#include "get_bits.h" + + +#define FRAME_HEADER_SIZE 64 +#define MAGIC_0 0x19 +#define MAGIC_1 0x68 +#define SUBSAMPLE_420 0 +#define SUBSAMPLE_422 1 +#define YUVORDER_YUYV 0 +#define YUVORDER_UYVY 1 +#define NOT_COMPRESSED 0 +#define COMPRESSED 1 +#define NO_DECIMATION 0 +#define DECIMATION_ENAB 1 +#define EOL 0xfd /* End Of Line */ +#define EOI 0xff /* End Of Image */ + + +typedef struct { + // The frame we decode into + AVFrame frame; +} CpiaContext; + + +static int +cpia_decode_frame(AVCodecContext* avctx, + void* data, int* data_size, AVPacket* avpkt) +{ + CpiaContext* const cpia = avctx->priv_data; + + // pointer to header frame data + uint8_t* const header = avpkt->data; + // pointer to frame data, will later point to the start of current line + uint8_t* src; + // size of remaining frame, will later be updated on each line + int src_size; + + uint16_t linelength; + uint8_t skip; + + int i,j; + // target data + AVFrame* const frame = &cpia->frame; + + // pointer to keep track where we are writing image dat + uint8_t *y, *u, *v; + + // Get buffer filled with previous frame + if (avctx->reget_buffer(avctx, frame)) { + av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed!\n"); + return -1; + } + + // Check header + if ( avpkt->size < FRAME_HEADER_SIZE + || header[0] != MAGIC_0 || header[1] != MAGIC_1 + || (header[17] != SUBSAMPLE_420 && header[17] != SUBSAMPLE_422) + || (header[18] != YUVORDER_YUYV && header[18] != YUVORDER_UYVY) + || (header[28] != NOT_COMPRESSED && header[28] != COMPRESSED) + || (header[29] != NO_DECIMATION && header[29] != DECIMATION_ENAB) + ) { + av_log(avctx, AV_LOG_ERROR, "Invalid header!\n"); + return AVERROR_INVALIDDATA; + } + + // Check for currently unsupported properties + if (header[17] == SUBSAMPLE_422) { + av_log(avctx, AV_LOG_ERROR, "Unsupported subsample!\n"); + return -1; + } + if (header[18] == YUVORDER_UYVY) { + av_log(avctx, AV_LOG_ERROR, "Unsupported YUV byte order!\n"); + return -1; + } + if (header[29] == DECIMATION_ENAB) { + av_log(avctx, AV_LOG_ERROR, "Decimation unsupported!\n"); + return -1; + } + + // data starts after header, set proper length + src = header + FRAME_HEADER_SIZE; + src_size = avpkt->size - FRAME_HEADER_SIZE; + + if (header[28] == NOT_COMPRESSED) { + // uncompressed frames are independent + frame->pict_type = AV_PICTURE_TYPE_I; + frame->key_frame = 1; + } else { + // compressed frames depend on previous frame + frame->pict_type = AV_PICTURE_TYPE_P; + frame->key_frame = 0; + } + + + // Data processing + for ( i = 0; + i < frame->height; + i++, src += linelength, src_size -= linelength + ) { + // Read line length, two byte little endian + linelength = AV_RL16(src); + src += 2; + + // Some integrity checking + if (src_size < linelength) { + frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM; + av_log(avctx, AV_LOG_WARNING, "Frame ended enexpectedly!\n"); + break; + } + if (src[linelength - 1] != EOL) { + frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM; + av_log(avctx, AV_LOG_WARNING, "Wrong line length %d or line not terminated properly (found 0x%02x)!\n", linelength, src[linelength - 1]); + break; + } + + /* Update the data pointers. Y data is on every line. + * U and V data on every second line + */ + y = &frame->data[0][i * frame->linesize[0]]; + u = &frame->data[1][(i >> 1) * frame->linesize[1]]; + v = &frame->data[2][(i >> 1) * frame->linesize[2]]; + + if ((i & 1) && header[17] == SUBSAMPLE_420) { + /* We are on a odd line and 420 subsample is used. + * On this line only Y values are specified, one per pixel. + */ + for (j = 0; j < linelength - 1; j++) { + if (src[j] & 1 && header[28] == COMPRESSED) { + /* It seems that odd lines are always uncompressed, but + * we do it according to specification anyways. + */ + skip = src[j] >> 1; + y += skip; + } else { + *(y++) = src[j]; + } + } + } else if (header[17] == SUBSAMPLE_420) { + /* We are on an even line and 420 subsample is used. + * On this line each pair of pixels is described by four bytes. + */ + for (j = 0; j < linelength - 1; ) { + if (src[j] & 1 && header[28] == COMPRESSED) { + // Skip amount of pixels and move forward one byte + skip = src[j] >> 1; + y += skip; + u += skip / 2; + v += skip / 2; + j++; + } else { + // Set image data as specified and move forward 4 bytes + *(y++) = src[j]; + *(u++) = src[j+1]; + *(y++) = src[j+2]; + *(v++) = src[j+3]; + j += 4; + } + } + } + } + + // Not quite sure how this data_size works + *data_size = sizeof(AVFrame); + *(AVFrame*) data = *frame; + + return avpkt->size; +} + +static av_cold int cpia_decode_init(AVCodecContext *avctx) +{ + /* We don't need to allocate memory for our context here. + * It is done by ffmpeg + */ + + // The pixel format this decoder outputs + avctx->pix_fmt = PIX_FMT_YUV420P; + + /* The default timebase set by the v4l2 demuxer leads to probing which is buggy. + * Set some reasonable time_base to skip this. + */ + if (avctx->time_base.num == 1 && avctx->time_base.den == 1000000) { + avctx->time_base.num = 1; + avctx->time_base.den = 60; + } + + return 0; +} + +static av_cold int cpia_decode_end(AVCodecContext *avctx) +{ + return 0; +} + + +AVCodec ff_cpia_decoder = { + .name = "cpia", + .type = AVMEDIA_TYPE_VIDEO, + .id = AV_CODEC_ID_CPIA, + .priv_data_size = sizeof(CpiaContext), // for ffmpeg to know how much to allocate + .init = cpia_decode_init, + .decode = cpia_decode_frame, + .close = cpia_decode_end, + .capabilities = CODEC_CAP_DR1, + .long_name = NULL_IF_CONFIG_SMALL("CPiA video format"), +}; diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c index 867c363..4b43688 100644 --- a/libavdevice/v4l2.c +++ b/libavdevice/v4l2.c @@ -150,6 +150,7 @@ static struct fmt_map fmt_conversion_table[] = { { PIX_FMT_NV12, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12 }, { PIX_FMT_NONE, AV_CODEC_ID_MJPEG, V4L2_PIX_FMT_MJPEG }, { PIX_FMT_NONE, AV_CODEC_ID_MJPEG, V4L2_PIX_FMT_JPEG }, + { PIX_FMT_NONE, AV_CODEC_ID_CPIA, V4L2_PIX_FMT_CPIA1 }, }; static int device_open(AVFormatContext *ctx) @@ -549,6 +550,13 @@ static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt) return AVERROR(errno); } av_assert0(buf.index < s->buffers); + + /* CPIA is a compressed format and we don't know the exact number of bytes + * used by a frame, so set it here as the driver announces it. + */ + if (ctx->video_codec_id == AV_CODEC_ID_CPIA) + s->frame_size = buf.bytesused; + if (s->frame_size > 0 && buf.bytesused != s->frame_size) { av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", @@ -767,7 +775,7 @@ static int v4l2_read_header(AVFormatContext *s1) AVStream *st; int res = 0; uint32_t desired_format; - enum AVCodecID codec_id; + enum AVCodecID codec_id = AV_CODEC_ID_NONE; enum PixelFormat pix_fmt = PIX_FMT_NONE; st = avformat_new_stream(s1, NULL); @@ -828,6 +836,14 @@ static int v4l2_read_header(AVFormatContext *s1) desired_format = device_try_init(s1, pix_fmt, &s->width, &s->height, &codec_id); + + /* If no pixel_format was specified, the codec_id was not known up + * until now. Set video_codec_id in the context, as codec_id will + * not be available outside this function + */ + if (codec_id != AV_CODEC_ID_NONE && s1->video_codec_id == AV_CODEC_ID_NONE) + s1->video_codec_id = codec_id; + if (desired_format == 0) { av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for " "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, pix_fmt); -- 1.7.9.5